The Orpheus Sector was a famed former Sector Imperialis whose status as a sector of the Imperium of Man was recently revoked by order of the High Lords of Terra following its devastation in the still-ongoing Orphean War. The worlds of the Orpheus Sector are counted amongst the oldest celestial bodies within the galaxy and its planets until recently hid a dark secret.
Yet, for four Terran millennia, the Orpheus Sector has also been a powerhouse of Imperial might, a stronghold at the outer borders of the Imperium. Located in the Dark Marches region of the Segmentum Tempestus and boasting its own proud history and Imperial Navy warfleet, the Orpheus Sector was first established in the 36th Millennium following the famed Dark Marches Crusade. Although its days of glory now rest in the past, the Orpheus Sector has defiantly stood on the Imperium's frontier despite being plagued by several strange Warp phenomena, xenos raids and Chaos-led uprisings.
However, everything changed when an old menace in form of the Maynarkh Dynasty awoke. Belonging to the vile breed of xenos known as Necrons by the Imperial Inquisition, this foe would lay waste the entire sector in a few short solar months, ravaging its worlds and conducting genocidal campaigns of extermination on a planetary scale.
With so many of its servants arrayed to combat the threat of the Tyranids in the Ultima Segmentum, the Imperium was left ill-prepared for the emergence of this new threat on its southern border. Ultimately, the Imperium was left with no other choice than to abandon the sector, hoping to eventually reclaim it when enough troops and vessels could be mustered to launch a proper Imperial Crusade.
Contrary to many of the Imperium's domains, which have existed for the last ten millennia, the existence of the Orpheus Sector as a fully recognised Sector Imperialis only dates back to the last century of the 36th Millennium. Like other regions in the galaxy, the planets of what would eventually become the Orpheus Sector were colonised by humanity during its first galactic expansion in what is referred today as the Dark Age of Technology. Contact with the wider Imperium was also established during the Great Crusade sometime between 570 and 750.M30 when the legendary Rogue Trader Lady Arica Orpheus ventured further than the Mandragoran Stars into the sector that would eventually bear her name.
Rogue Traders usually function as scouting elements for far larger and military-minded fleets, and in this the voyages of Lady Arica were no exception. Soon the Expeditionary Forces of the Great Crusade followed in Lady Orpheus' wake, determined to reestablish contact with those few scattered human civilisations that had survived the Long Night and the baleful attention of xenos raiders. Some of these alien races had successfully established their own pocket empires in the region and would need to be exterminated, but for the most part the Dark Marches as they were then still called were a barren and desolate streak of the galaxy.
The vast majority of these worlds were tremendously old, incapable of sustaining human or xenos life, but many bore the tell-tale signs of former biospheres and unknown civilisations. The surviving records of the Lady's later voyage -- now safely guarded within the Great Covenant Navis Temple on Terra -- speak of her discovery of gargantuan xenos ruins across the region. It was also at this time that the world of Amarah Prime was colonised by Lady Orpheus' fleet, acting both as a supply point and safe haven for her own later voyages and the forces of the Great Crusade tasked with pacifying the region.
It is worth noting that even in this distant time, Imperial forces suffered from frequent raids from the Drukhari, who have probably been preying on the worlds of the Dark Marches Region for millennia. As Lady Arica ventured ever closer to the galactic border, she finally reached the turbulent area of the galaxy known as the Veiled Region which proved too dangerous to cross, thus marking the outer limit of her voyages.
While the Rogue Trader's work was complete, the work of the Imperial Army and the Legiones Astartes was not. Unfortunately the Imperium soon descended into the time of chaos, civil strife and anarchy known as the Horus Heresy before any further settlement of the Dark Marches could commence.
The Horus Heresy
When the Imperium was torn apart by the civil war that followed the Warmaster Horus' betrayal, the Orpheus Sector was largely abandoned to its fate, as neither Loyalists nor Traitors displayed much interest in this far-flung region of space during the conflict. Those xenos domains not yet eradicated by the forces of the Great Crusade surged forward and the Dark Marches quickly became a lawless borderland where renegades and xenos corsairs roamed freely. Only the Imperial outpost on Amarah Prime continued to enjoy some measure of stability, but it would not last indefinitely.
Somewhere during the first century of the 31st Millennium, a Traitor warlord by the name of Dynat Mal -- originally belonging to the Alpha Legion -- chose the Dark Marches as a safe haven to escape the press of those armies loyal to the Emperor which had launched a new crusade known as the Great Scouring. Having gathered a thousand strong coterie of Renegades, Heretics and diabolists around him, Dynat Mal's warband took the name of The Shadowed Ones and destroyed the Imperial outpost on Amarah Prime, plundering its stores and stockpiles after having massacred the outpost's entire population. Several punitive expeditions launched by the reemerging Imperium were destroyed through the use of guerilla tactics and the baleful powers of Chaos.
With the destruction of the outpost on Amarah, any Imperial claim to the region was effectively severed. Yet the Imperium could not so easily let a known foe roam its borders freely. The Raven Guard Chapter still sought to avenge the deaths of their fellow Legionaries during the Battle of Lyx, for which Dynat Mal was responsible. Around the year 170.M32, the Raven Guard despatched a sizeable taskforce under Captain Kallengier to bring Dynat "Crowbane" Mal to justice.
Yet, despite intensive search and reconnaissance, the Alpha Legion still eluded the vengeful Raven Guard until the task force reached the heart of the Orpheus Sector. There, in the deep jungles of the world of Apollyon, the Raven Guard Astartes discovered the broken hull of a Strike Cruiser quickly identified as the Occam's Razor, known to have belonged to the XX Legion's fleet. While the Strike Cruiser's demise could not be ascertained for sure, the surroundings of the broken warship were still more unsettling -- like a grim tombstone or grave marker, the Occam's Razor stood over a valley filled with the bones of the dead.
The corpses mostly belonged to mutated humans but also to the Aeldari, to the Khrave and to several other unidentified xenos forms. Most disturbing of all, however, were the sundered warplates of the Astartes which not only bore the colours of the Alpha Legion, but also those of the White Scars and the Iron Hands. The identity of the perpetrator of the massacre remained unclear and the Raven Guard did not linger long, for their Librarians’ visions told of an impending doom should they remain at the site. Their vengeance denied once more, the Raven Guard departed the baleful valley, their questions unanswered.
In the millennia that followed, the Dark Marches were utterly neglected by the Imperial authorities and left to fend for themselves. Very few facts can be verified about what occurred in the region during this period as the Segmentum Tempestus is frequently isolated by powerful Warp Storms and other stellar phenomena. It is only in the wake of the Age of Apostasy that the eye of the Imperium once again rested on those worlds that would soon become the Orpheus Sector.
The Rising Storm and the Birth of the Orpheus Sector
Whereas other regions of the Imperium were weakened by the events of the 35th and 36th Millennia, the Segmentum Tempestus knew a period of stability. The strong Warp Storms that had given the Segmentum its name were slowly abating and with the end of Goge Vandire's Reign of Blood and the death of the usurper, the Imperium turned its eyes to the Dark Marches Region.
With the approval of the High Lords of Terra, the Segmentum authorities declared a series of interlinked campaigns and crusades to rid themselves of xenos plagues and other menaces, but also to fortify the Imperium's borders. It would take some time before the Imperium ventured into those regions that had been left abandoned since the Horus Heresy, but following the launch of the Dark Marches Crusade, the Dark Marches Region became a primary focus of the Imperium's drive for expansion.
Although the Crusade would take nearly a solar century and a half to reach its conclusion, the Dark Marches Crusade would prove a great victory. It would culminate with the formal creation of the Leyak, Hazak and Eurydice Sectors as well as the Orpheus Sector. This name was chosen as an homage to both the Rogue Trader Arica Orpheus who had first explored this region of space and to the crusade's mastermind, Lord Tempestus Hal Orpheus, who became the new Sector's first appointed Governor. The former Imperial outpost on Amarah Prime was rebuilt and soon became the Sector's new capital world where the aging Lord Tempestus built his palace.
But the Orpheus Sector remained a frontier region of the Imperium, a realm with no august name to draw settlers to it and where life proved particularly harsh and dangerous. The uninhabited system of Myre was given over to the Adeptus Mechanicus which soon began to exploit the system's riches and thus laid the foundation of the sector's trade-routes. Other worlds were given over to victorious regiments of the Astra Militarum that had participated in the Dark Marches Crusade, claiming by Rite of Conquest what they had fought and bled for.
However, apart from zealous pilgrims and the warrior-priests of the Frateris Militia, few other colonists followed. This ran counter to the High Lords of Terra's plans. Soon entire planetary populations were placed under an Edict of Transmission and were forcibly transported across the galaxy to their new home in the Orpheus Sector. Most notoriously, millions of Imperial citizens were brought in from the overcrowded Hive Worlds of the Warre and Uhulis Sectors, while refugees from distant worlds ravaged by war or environmental degradation were rerouted to colonise the Orpheus Sector and its neighbours.
These new colonists formed the core of the new population of the Orpheus Sector. To better protect the sector's rapidly expanding trade routes, the people of Orpheus were gifted the right to form their own Imperial Navy warfleet, the Battlefleet Orpheus, whose mighty flagship, the Apocalypse-class Battleship Arica Dominus had once carried Lord Tempestus Hal Orpheus into battle. The battlefleet soon took the Lantern of Orpheus as its official symbol, a design believed to have been derived from the personal heraldry of Lady Arica Orpheus in whose honour the Arica Dominus had been named.
For more than a millennium, the Orpheus Sector knew nothing but prosperity, an era that is now seen as something akin to a first Golden Age. With the sector's first millenial anniversary close at hand, the entire sector rejoiced, ordinate, commoner and noble alike celebrating the good fortune of the ever-growing sector which had quickly risen to prominence amongst the other sectors of the Segmentum Tempestus. As part of the celebrations, the preserved corpse of Hal Orpheus, now regarded as the spiritual father and founder of the Orpheus Sector, was borne upon the Arica Dominus to complete a tour of the sector's most influential worlds. Many holy miracles and visions were reported to have occurred in the wake of the relic-corpse's passage.
Yet, in a relatively short period of time, the atmosphere of optimism and religious zeal of the Orpheus Millenial was replaced by one of wary caution. When in 976.M37 all contact was lost with the neighboring Leyak Sector, the High Lords of Terra declared several edicts that would see the Orpheus Sector prepared for war. The sector's wealthiest worlds began to fortify themselves, securing their domains by raising new regiments and investing a large portion of their wealth and industrial output into orbital defence platforms.
Battlefleet Orpheus also greatly benefited from this build-up, both in terms of manpower and warships made available as the ever more paranoid sector authorities diverted their growing resources to their own defence. By Imperial Edict several Frontier Worlds of the sector were declared Perdita and Imperial citizens were barred from trespassing upon them under pain of death, but the huge expenditures on a military build-up ultimately led to increasing political instability within the sector.
While the sector continued its military build-up, the heavy tithes imposed to finance the naval expansion bred considerable social discontent and the Adeptus Arbites and the Ordo Hereticus were frequently called upon to conduct social purges or violently reprimand any outbursts of an anti-Imperial nature. Reports of Chaos Cult activities steadily rose in frequency across the sector, but the first true test of the region's defences did not come from the Outer Darkness or from the silent Leyak Sector as had been long feared, but from within.
The Time of Woes
While the Orphean Admiralty focussed on surveying their border with the Leyak Sector and dousing the brush fire revolts within the populace that steadily destabilised the sector over the following centuries, the Orpheus Sector was also the source of countless inexplicable tragedies. By the beginning of the 38th Millennium, the Orpheus Sector had effectively become a tinderbox, waiting for the inevitable spark to ignite it. This spark was not an alien attack from without as Segmentum authorities had feared, but from within, when the Renegade Von Mallas pronounced his war of faith.
Originating in the Segmentum Pacificus, the teachings of "The False Saint" or "The Transgressor" as he came to be known in the years that followed, fell upon fertile ground within the Orpheus Sector and in other locations of the Segmentum Tempestus. Entire star systems and worlds declared for the Transgressor as did both the Hive World of Colkasth and the Agri-World of Epirus. The regiments and troops bound to survey the sector's borders soon were called upon to prosecute a campaign against what the Ecclesiarchy had dubbed the Von Mallas Black Crusade.
War soon engulfed the Orpheus Sector. Resistance proved fierce, especially on Epirus which was devastated by the fighting and would take decades to recover even a shadow of its former productive capacity. When the Renegades were finally subdued, the sector authorities founded the Penitentiary World of Morros Lachrymal to harbour those who would rather toil in atonement for their sins than face the pyres of the Ecclesiarchy and the Ordo Hereticus.
While the immediate crisis had been adverted, the devastation of Epirus would prove to be an entirely separate catastrophe. The loss of the Agri-world's output bore heavily on the sector's trade. The loss of an entire harvest could perhaps have been borne, but the reconstruction of Epirus would take many standard decades, thus considerably affecting the supply of foodstuffs to the Capitoline Sub-sector. Famine and pestilence soon became the Orpheus Sector's worst enemies as increasing Warp Storms made importing goods from other sectors more dangerous and expensive.
This did not fail to breed considerable bitterness within the sector's population, which gradually turned away from the orthodoxy of the Imperial Creed. Heretical cults and sects rose in power during these dark years, the most notable of which were the Celestarii. First encountered in 715.M38, the Celestarii were heavily persecuted by both the Adeptus Arbites and the Ordo Hereticus but proved to be extremely difficult to root out, for the cult preyed on the desperation of the common folk. What made the Celestarii so subversive was that they had renounced the Emperor's divinity, claiming that the galaxy's true masters were in fact immortal beings that had fallen into an eon-spanning slumber but would eventually rise again and reward their followers with immortal life.
To those that would oppose them, these sleeping gods would bring only death. The cult, which several investigations revealed indulged in cannibalistic rituals, had taken some of the xenos artifacts that the sector harboured in great quantities as their sacred relics. But, in truth, the cult mostly worked to further the power and enrichment of its inner circle rather than openly challenge the central place of the Imperial Creed. The Celestarii's ranks were considerably reinforced following the mysterious fate that befell the world of Tlaloc.
Located at the very edge of the Orpheus Sector in the Drucillan Sub-sector where it borders the Leyak Sector, the world of Tlaloc has always been regarded as a dangerous place. Segmentum and sector authorities still remembered the lost colonisation fleet that vanished in the 36th Millennium near the world, but this left them unprepared for the vents of 889.M38. Garbled distress signals emanating from Tlaloc were received by the Imperial authorities, which promptly rerouted a squadron of Battleships from Battlefleet Orpheus to investigate the matter. Before being abruptly cut off, the distress signal had warned of an impenetrable darkness and unspeakable massacres.
Upon its arrival, the squadron found the world in ruins -- Tlaloc had been turned into a charnel house. Landing parties reported blood-splattered streets and walls and still-burning ruins. Neither bodies nor data could be recovered from the remains. Whatever brought Tlaloc to its knees had done so in a matter of a few solar hours. Tlaloc's proximity to the lost Leyak Sector spawned much speculation in the Imperial High Command, which warranted an official investigation led by Inquisitor Kussan of the Ordo Xenos.
The Inquisitor interpreted the lack of physical remains of the victims on Tlaloc as evidence of the actions of Drukhari corsairs. Yet, the Orphean Admiralty and the sector's other Inquisitorial Ordos disagreed with Kussan, fearing the involvement of a very different force, perhaps the unknown enemy who was also responsible for the loss of the Leyak Sector. As a precautionary measure, the sector's Imperial Commander decided to quarantine what remain of Tlaloc, a quarantine maintained until the beginning of the Orphean War.
The Orpheus Sector entered the 39th Millennium in the same state as it left the tumultuous 38th: on the verge of open conflict. While the sector no longer suffered from agricultural supply issues and no famine had visited the Orpheus Sector for many standard centuries, the worlds of the Orpheus Sector -- still burdened by the arduous military tithes they were subjected to--were fractured, no spirit of kinship or loyalty existing between them. The sector governorship had long since passed from the extinct line of House Orpheus to the stewardship of the House of Laan, distrusted by many due to its scions' reputation for intrigue and excess.
To some extent, the sector was kept solvent only by the tireless efforts of the officers of the Battlefleet Orpheus, which successfully averted several crises that might have plunged the sector into chaos. For instance, in 160.M39, a powerful Ork-fleet, led by a gigantic flagship -- the so-called "Mega-Kroozer" -- entered the Orpheus Sector from the galactic South. Battlefleet Orpheus tirelessly engaged the enemy, fighting the Orks in a running battle for nineteen solar weeks on the edges of the Deluvian Sub-sector.
With the help of reinforcements from the Adeptus Astartes, including contingents drawn from the Revilers and Red Seraphs Chapters, the Greenskin threat was eliminated. Yet some of the Orks managed to escape destruction and found shelter in the great debris-fields on the edge of the Sub-sector, raiding and harassing Imperial worlds and convoys. But even though the Orks proved a recurring thorn in the side of the sector's trade and commerce, its worlds lacked the common will to pull together and expunge the threat once and for all.
The Orphean War of Faith
At the end of the 39th Millennium, the Orpheus Sector was trapped in a deep state of neglect, its defences overstretched and its planetary governments in political disarray. On Amarah Prime, the last scion of the sector's founding dynasty, the line of Orpheus, died out, and the sector's governance had passed to the dissolute House of Laan. Lacking the political acumen of other houses, the rule of the House of Laan over the sector was fragile at best, and ill-suited for the hardships to come.
With the Haxan Wars still raging in the neighbouring Haxan Sector, the Orpheus Sector's military resources fuelled the Imperium's fight against the Apostate Hepstad and the Drukhari Slaughtervane Kabal. At the same time, the sector needed to tend to its own defence as both xenos -- the descendants of the Ork incursion of 160.M39 -- and Renegade raiders plagued the Drucillan and Deluvian Sub-sectors. Unable to keep these menaces in check, tensions over Imperial tithes and the cost of the ongoing war degenerated first into campaigns of petty vendettas and assassination, and later into outright civil war between entire worlds.
Open conflict erupted when the honour-clans of the Drucillan Cluster overthrew their local opposition and declared their secession from the Orpheus Sector. The cluster's principal world, Drucilla Majoris, quickly becomes a haven for other Renegade fractions within the sector, posing an ever-growing threat to the region's stability.
In the Deluvian Sub-sector, feeling threatened by its neighbours, the Parliament of Amraphel intended to conduct a preemptive strike against its rivals. Seeking to maintain deniability over its illegal actions against fellow Imperial worlds, the Parliament called upon xenos mercenaries to do their dirty work, only to discover that these mercenaries were in fact a splinter-web of the dreaded Khrave. The Khrave devoured the conspirators' minds and added Amraphel's rulers to their larders before using their influence to subdue Amraphel's population. As the number of mysterious disappearances increased over the following solar months, the Adeptus Ministorum uncovered the truth and lead the population in an uprising to rid Amraphel of the xenos taint that had befouled it.
If all this were not enough, it soon became obvious that -- as in the Haxan Sector -- the malign taint of Chaos was the root cause behind a series of brushfire conflicts and revolts. To regain control over this precarious situation, Imperial Guard regiments needed to be brought in, but after several early successes, the Imperial troops encountered hordes of mutants fighting alongside the Heretics and rebels. On the worlds of Apollyon and Selakhar, the Guardsmen also encountered foul daemons. This encounter acted as a catalyst for the fractious ruling classes of the sector to put their own interests aside and unite, ultimately leading to the Orphean War of Faith.
This conflict was sparked by the arrival of a person of great importance, Arch-Confessor Marduk of Helvamon, later canonised by the Ecclesiarchy for his vital part in the Orphean War of Faith. Led by visions of the God-Emperor Himself, Arch-Confessor Marduk had declared a War of Faith for the souls of the Orpheus Sector, his visions warning him of a terrible menace to the Imperium, "...rising where the light of Orpheus falls forever in shadows." In 903.M39, the ramshackle Marduk fleet arrived within the Orpheus Sector. Marduk's fiery orations, ecstatic visions and martial fervour had gathered a crusading force around the Arch-Confessor.
This army, numbering many hundreds of thousands strong, was not merely made up of Imperial zealots or pilgrims, but also held many trained militia-men and even seasoned Imperial Guardsmen in its ranks. However of even greater strategic importance was the presence of the Arch-Confessor himself, as Marduk soon became a potent rallying point for those who opposed the forces of darkness.
With the arrival of Arch-Confessor Marduk, the Imperial war effort gained momentum. In the sector's east, thus far untouched by the growing turmoil, countless ordinary citizens soon swelled the ranks of Marduk's crusading forces, inspired by the Arch-Confessor's vision and emboldened by his public speeches. One by one, the sector's secular and spiritual authorities rallied around the inspirational Arch-Confessor, and he led his crusade along the route now known as the Orphean Pilgrimage.
When the baleful presence of daemons was confirmed and several warbands of Chaos Space Marines were conclusively identified, the Imperial Crusade was reinforced by contingents drawn from the Adeptus Astartes, the Adeptus Ministorum and the Inquisition. To counteract the corrupting influence of the daemons, the Ordo Malleus despatched a full taskforce -- believed by many to have also contained Battle-Brothers of the Grey Knights as well as Inquisitorial Storm Troopers and Inquisitors.
The most numerous of these reinforcements were the Space Marines of the Angels Revenant, whose entire Chapter answered Marduk's call, and the Sisters of Battle of the Adepta Sororitas, whose contingents were drawn from the Order of the Valorous Heart and the Order of the Black Sepulchre. Despite this infusion of fresh troops, the Orphean War of Faith raged for nearly twenty standard years, ravaging the sector's economy and several of its worlds, until by 921.M39 the Chaos-aligned fractions had been pressed back to their fortress of Colkasth.
On this former Hive World, the Chaos warband known as the Deathmongers had settled, their Warpsmiths turning the world into a living hell. Colkasth's population had been used as raw materials for their abominable plans. Former Imperial citizens had been warped by the powers of Chaos into living flesh-weapons, mutilated and insane cannon-fodder intended to fight and die in the battle that would follow. In contradiction to any sane military tactics, Arch-Confessor Marduk decided that his assault forces on Colkasth would be entirely human.
He despatched his allies from the Adepta Sororitas and the Adeptus Astartes away from his fleet to harass, and destroy those Traitor elements already vanquished or retreating. Faithful to their oaths, they did not question the orders of the Arch-Confessor and thus the last battle of the Orphean War of Faith began without their aid. From the final communications received, it is known that Marduk's offensive met with initial success, the crusading soldier-zealots holding back the fury of the daemons with fire and faith and establishing several landing zones on the planet's surface before astropathic contact with the besieging Imperial army was abruptly lost.
The first ship to reach the system after all contact with Marduk's fleet was lost was the Intercessor, an Adeptus Astartes Strike Cruiser belonging to the Angels Revenant. As soon as the Intercessor had cleared the system's Mandeville Point, the mighty vessel was attack by two unidentified, yet smaller vessels which proved extremely agile and powerful. It is largely accepted that the vessels neither belonged to the Imperium, nor to their Chaos opponents, and must thus have been of xenos origin.
Severely damaged, the Intercessor remained victorious, destroying one attacker and forcing the second to retreat, but the Strike Cruiser was virtually crippled in return, its engines badly damaged. Reduced to travelling at a frustratingly slow pace, the Intercessor could only witness a great naval clash in the inner system on its long range Augurs, with the Angels Revenant powerless to intervene. Only solar hours later did the limping vessel reach Colkasth's orbit, where it found the world's cities and fortresses shattered, great parts of the world's surface engulfed in radioactive flame. The Imperial armada likewise lay in ruins, reduced to a great orbital field of burning debris and gutted hulks.
The attackers were long gone, their motives and identity unknown. The Angels Revenant boarded the destroyed Imperial vessels in search of clues and discovered some scattered groups of survivors amidst the fleet's wreckage and the fallout-shrouded cinders of the world below. Those who bore the stigmata of Chaos the Space Marines immediately put to the sword, while those survivors who had fought for the Emperor the Angels Revenant carried to safety. Unfortunately, Arch-Confessor Marduk was not counted amongst these survivors and the priest was soon beatified by the Holy Synod of the Ecclesiarchy, an honour which warranted a change of name for the black, ash-shrouded world that would stand mute testimony to the Arch-Confessor's ultimate failure: Saint Marduk's Bane.
Despite the untimely death of Saint Marduk, the Orphean War of Faith is still celebrated as a great success, having averted the sector's fall and expunged the Chaotic menace. In the following decades, the Orpheus Sector slowly rebuilt its might, greatly aided by the remaining followers of the martyred Saint. By special dispensation of the Segmentum authorities, many regiments of the Imperial Guard were allowed to settle within the region, either returning fully to civil life or by incorporating the seasoned and battle-hardened regiments within existing or newly created Planetary Defence Forces. This influx of able men, many of whom could boast military experience, greatly strengthened the sector's defences.
In honour of the fallen soldiers and Saint Marduk, the minor colony world of Libertha, of which the late Saint had been particularly fond, was elevated to the rank of Shrine World in order to celebrate the Orphean War of Faith's blessed dead. These numbered in the millions, as the sector had lost a fifth of its overall population during the conflict. To further strengthen the sector's defences, the fleet-based Angels Revenant Space Marine Chapter was given stewardship over Libertha, their fortress-monastery built amongst the rows of tombs, mausoleums and Basilica to be erected on the Shrine World.
The Inquisition, and in particular the Ordo Malleus, also established a permanent position within the Orpheus Sector, as many millions of refugees and survivors needed to be examined and relocated, or if need be, purged from the population. With typical zeal, the servants of the Inquisition laid a heavy hand on those worlds fallen to corruption or conquest by the forces of the Archenemy. It came as no surprise that the world of Apollyon in the Capitoline Sub-sector, which had seen several daemonic incursions and Warp breaches, was given over to the sole control of the Inquisition.
Thanks to these additions to its defences, the Orpheus Sector entered a golden age of expansion and prosperity which lasted for many centuries. Yet, in the wake of the Orphean War of Faith, many raiders sought to prey on the resurgent sector and many conspiracies were unveiled by the diligent hands of the Inquisition. Slowly, as the centuries passed, and enemies like the Orks supplanted the Chaotic threat, the existence of the mysterious foe responsible for the death of Saint Marduk's crusade receded from memory. The "Sleepers of Orpheus," as they had come to be called, slowly faded into myth and dark legend, their baleful power forgotten.
During the 40th Millennium, the Orpheus Sector continued to prosper and to weather a myriad of crises. In 319.M40, the southern regions of the Orpheus Sector fell prey to a WAAAGH! led by the Ork Warboss Badrok Gutgouga of the Evil Sunz klan. In a gruesome seven solar month-long campaign, the Orks were finally cornered on the world of Lysmarchus. The armoured regiments of the Imperial Guard drawn from the distant world of Koenig encircled the Orks and systematically annihilated them with the support of the Orpheus Sector's defence forces. As a grand gesture of victory, the Ork Warboss' carcass was taken from the battlefield and publicly hanged from the spire of the Red Cathedral on Amraphel, marking the beginning of celebrations throughout the entire Deluvian Sub-sector.
On the wider scale of the Segmentum, and indeed the entire Imperium, the Orpheus Sector is widely recognized for its contribution to the Great Severan War, which ravaged the border regions of the Segmentum Tempestus and the Ultima Segmentum from 580 to 591.M40. In a great muster of armies, commonly referred to as "the Emperor's Due" by the Amaranthine Courts, the Orpheus Sector placed over thirty-nine million men and women under arms and at the disposal of the Imperial Guard. Few of these new regiments ever returned to the Orpheus Sector, but their sacrifice was commemorated on Libertha by the raising of the Basilica Severan. As part of this further militarisation of the sector, the Penitentiary World of Morros Lachrymal, previously a mining facility, was devoted to the training of Penal Legions.
Yet the prosperity of the Orpheus Sector had a downside, as other worlds rose to prominence. Amarah Prime's status as the capital world of the entire Dark Marches Region was increasingly contested, mostly on the Hive World of Decapolis, a thriving planet in the sector's galactic west. By the middle of the 40th Millennium, Decapolis' population and economic output had effectively surpassed Amarah Prime's. But due to tradition and practice, Amarah nevertheless remained the sector's capital world, harbouring not only the seat of the Imperial sector governor, but also the headquarters of the sector Administratum and of Battlefleet Orpheus.
Using their influence with the Administratum, the Amaranthines imposed increasingly heavier tithes on Decapolis, hoping to hinder the world's growth and retain their ancestral position of power. This led to considerable resentment within the mercantile and military castes of Decapolis, to the point where even Decapolis' ruling council of Decrachs increasingly chafed at Amarah's ever-growing demands. As is often the way in these things, resentment quickly turned to hatred, which soon blossomed into conspiracy. The Decrachs hatched a considerable number of plans to destabilise Amarah's planetary government and supplant it so that sector-wide authority would be transferred to Decapolis. These plans consisted mainly, but not only, in the covert funding and arming of several groups of political dissidents, smuggler rings and heretical groups such as the Cult Celestarii.
These groups were intended to conduct a planned campaign of assassination and terrorism. The conspiracy was discovered when the Inquisition's Ordo Hereticus captured several members of a Celestarii cell and put them to the question. Undeniable proof of the Decrach's involvement was provided when a heavy weapon crate in the cult's possession was traced back to a manufactorium on Decapolis.
The Decapolis Conspiracy, as it became known, demanded immediate retaliation and harsh punishment. The Inquisition descended swiftly on Decapolis and conducted a series of systematic and thorough purges. The accused were publicly condemned in a series of show-trials that lasted for nearly nine standard years. The entirety of the Decrachs fell prey to these purges, and outright revolt or even civil war was only prevented through the ruthless application of the Inquisition's oppressive methods. But by then the damaged had been done.
Identification and death of the primary instigators of the Decapolis Conspiracy failed to better the situation on Amarah itself. The Amaranthine population perpetuated the belief that secretive forces were working to the world's detriment, which lead to several incidents of public unrest. This paranoia also gained purchase in the Amaranthine Court when the Sector Governor imposed even heavier tithes on the seditious world of Decapolis to further weaken Amarah's principal rival.
This in turn fuelled resentment on Decapolis. Over the following decades, this climate of tension would spread throughout the entire Orpheus Sector, seizing its worlds in an unshakable grip of discord and distrust. Gradually, the worlds of the sector began to turn in upon themselves. The Orpheus Sector's hard-earned unity was shattered, and later historians marked the Decapolis Conspiracy as the event that brought the sector's golden age to its end.
Portents of Doom
It was in this state of disarray that the Orpheus Sector entered far more tumultuous times. With the local political powers squabbling, it fell to the sector's foremost defenders to maintain some measure of stability within the region.
However, this task grew more complicated in 672.M40 when the Orpheus Sector was increasingly plagued by sudden and unpredictable Warp squalls, aetheric disruptions or other strange phenomena of the same ilk. These were not isolated incidents, as much of the Segmentum Tempestus was suffering from the same problems at this time. The Warp had grown restless, and even safe and established routes were not spared from the rise in unusual aetheric activity. Many voidships were lost in the Warp, so many that commerce within the sector rapidly declined, and inter-system ship traffic was gradually reduced to a historic minimum. Only the vessels of Battlefleet Orpheus and the Angels Revenant tirelessly continued their patrols. However, the increased Warp activity also bore dire consequences for the physical realm.
This untamed Warp energy was held responsible for many natural disasters in the sector, but most notoriously it spurred Chaos Cults to action. At the same time, psyker-daemon incursions rose to levels the Sector had not seen since the Time of Revolts. On many worlds, latent psykers and psychically-sensitive Imperial citizens reported recurring nightmares, all painting a bleak picture of a rising darkness and burning cities. Some told of pale figures treading in eerie silence in the dust of dead worlds, or stalking immense labyrinths, malice written in their eyes. These unsettling reports quickly came to the ears of the Inquisition, which immediately tried to suppress wider knowledge of the visions. Emboldened by these aetheric disturbances, the Eldar Corsairs of the Hesod Nebula also increased their raids on the sector, preying upon the worlds of the Cold Veil and the Capitoline Sub-sector alike.
In the end, the power of the Empyrean gave birth to a full Warp Storm, the Howling Vortex, which engulfed the system of Morros in 689.M41. All communication with the penitentiaries of Morros Lachrymal and its thirteen million prisoners was lost, their fate unclear, as were the fates of the last prison-hulks despatched by Decapolis.
It is generally assumed that the vessels, like so many others of that time, perished in the Warp. At the same time, the Celestarii Cult emerged from the shadows and redoubled its activities, culminating in the famed Kellerman Murders of 744.M41. With the sector's rulers still openly distrustful of each other and unable to set their differences aside, the Inquisition, already overstretched, failed to prevent a Chaos-inspired uprising on the industrial worlds of Chemarium. The sector lacked the strength to smash the rebellion and the worlds of the Chemarium System were cordoned off, its loyal citizens and cities left to fight the threat alone.
These events perhaps explain why no importance was given to an incident of 811.M41 in the distant system of Harrow Watch, at the exterior borders of the Orpheus Sector. The Wayward Son, an Escort-sized Warp dromon of the Rogue Trader flotilla of Caleb Gilderoy, unexpectedly returned from the Outer Darkness, limping into the Harrow Watch Exclusion Zone. The voidship was heavily damaged, and what garbled communication could be received at the Mechanicum outpost indicated that its crew claimed to have been attacked by unknown xenos. This "terror" had wiped out the rest of the Rogue Trader's flotilla.
The communication ended in desperate pleas for immediate sanctuary at Harrow Watch, but as the voidship did not carry the proper authorization codes to enter Harrow Watch's defence perimeter, the Wayward Son was destroyed by the Mechanicum for having failed to comply with the Magos' orders to turn back.
The Wayward Son-incident was unique, but was representative of the increasing number of vessels lost at the Orpheus Sector's outer borders. Since the Harrow Watch System is close to the Hesod Nebula, the losses were attributed to Eldar Corsairs rather than to another possible xenos foe of the Imperium. Even when operatives of the Inquisition ascertained that the Cult Celestarii awaited the imminent End of Time, this news was not taken seriously or linked to the other strange incidents in the sector. In hindsight, it appears that these events heralded the awakening of the Necron menace. Alas, all of the most obvious signs were misinterpreted.
After plaguing the Orpheus Sector for more than three hundred standard years, the increased Warp activity and other strange phenomena were suddenly snuffed out by a tremendous Warp Storm. Many voidships were driven off-course by the storm, emerging in star systems far distant from their original destination, some reemerging violently in realspace or dropping out of the Warp unexpectedly, while others were simply destroyed, broken apart by the force of the Immaterium, the souls of their crew and passengers fodder for daemons.
All across the sector, astropaths, psykers, hedge-wizards and witches suffered inexplicable death or had their minds burned blank by the stress put on them. Even mundanes were affected as the cases of mass hysteria, mania, inexplicable murders or disappearances in the Cold Veil region and the Drucillan Sub-sector testify. Believing the Warp Storm to be but a precursor of a larger daemonic incursion from Apollyon, the Ordo Malleus and the Conclave Orpheus issued a warning for maximum vigilance among their Inquisitors and Acolytes.
So it was that at the end of the year 990.M41, these urgent messages supplanted a communication from the distant Mechanicum outpost of Harrow Watch, a message which warned that both suns of the binary Caracol System beyond the Veiled Region had gone supernova at the same time that the Warp Storm hit the sector's outer limits. This report was largely dismissed at the time as insignificant.
No one within the Ordos thought of cross-referencing the destruction of the Caracol System with the sacred text of the Cult Celestarii, which had foretold that these stellar catastrophes would herald the End of Time. In hindsight, these events can be clearly interpreted as unheeded warnings portending the awakening of the Maynarkh Dynasty that ultimately destroyed the sector in the Orphean War. One cannot help but wonder that if the data had been correctly interpreted and swift action taken, perhaps the Orpheus Sector would still exist today.
Orpheus Sector Timeline
- The Voyages of Orpheus (ca.570-750.M30) - As part of the Emperor's Great Crusade, the Rogue Trader Lady Arica Orpheus mounts several far-ranging expeditions into the Dark Marches region of the galaxy that would eventually become the Orpheus Sector. With the foundation of the Imperial outpost on the world of Amarah Prime, the Imperium officially claims the Dark Marches region. Several military campaigns follow to exterminate identified xenos threats, but the sector is still not entirely pacified when the Horus Heresy plunges the Imperium into galactic civil war.
- The Sundering of the Imperium (005.M31-020.M31) - Following the Great Betrayal and the descent of the Horus Heresy and its Age of Darkness upon the domains of the Imperium of Mankind, both Loyalists and Traitors alike retire from the region, leaving its colonists to fight for themselves. Although no great battles are fought in the Orpheus Sector, the population suffers from resurgent xenos and Dark Eldar raids.
- The Scourge of Dynat Crowbane (pre-100.M31) - Driven outwards by the resurgent armies of the Emperor of Mankind after the Battle of Terra, an Alpha Legion warlord known as Dynat Mal, the main architect of the Raven Guard's humiliating defeat at the Battle of Lyx, seeks shelter in the Dark Marches. Having destroyed the only semblance of organised resistance in the region, the Imperial outpost on Amarah Prime, Dynat Crowbane and his warband reign over the sector. Calling themselves "The Shadowed Ones", they repel several punitive expeditions sent to destroy them.
- Vengeance Denied (ca.170.M32) - A punitive taskforce of the Raven Guard Chapter under Captain Kallengier is despatched to destroy "The Shadowed Ones" and their master, but only discover the ruins of Crowbane's ship, the Occam's Razor, buried in thousands of tons of bones and corpses.
- The Child of the Beast (552.M32) - As part of a great migration of Orks that plague the entire Imperium, an Ork-crewed Space Hulk known as Da Iron Worm vanishes in the Dark Marches region after having laid waste to several powerful worlds in the Uhulis Sector.
- The Rising Storm (610.M36) - Following the tumultuous Age of Apostasy and the death of Goge Vandire, the Segmentum Tempestus knows a resurgence in power and fortune. With the tremendous Warp Storms that had given the Segmentum its name now abated, Segmentum authorities launched a series of campaigns and Imperial Crusades designed to expunge lingering threats and fortify the Imperium's borders. This was only possible because of the relative calm that reigned within the Segmentum, whereas other domains of the Imperium such as the Segmentum Solar or the Segmentum Obscurus had been weakened by other conflicts. The eye of the High Lords of Terra soon came to rest on the wayward Dark Marches region and marked it for conquest, the dangers of the past forgotten.
- The Dark Marches Crusade (610-759.M36) - The Dark Marches Crusade is but one of the campaigns launched during the Rising Storm that would lead to the birth of the Orpheus Sector. After having served as an advance port for the Crusade for nearly thirty standard years, the world of Amarah Prime is chosen as the sector's new capital.
- The Lost Fleet (817.M36) - A colonisation fleet carrying some sixteen million human colonists bound for the verdant fen-covered world of Tlaloc mysteriously vanishes, never to be seen again.
- The Colonisation of Tlaloc (ca.847.M36) - A second Imperial colonisation fleet -- much smaller than the one that vanished before -- successfully reaches Tlaloc and settles on the world.
- The Orpheus Millenial (759.M37) - To celebrate the 1,000th anniversary of its creation, the entire Orpheus Sector rejoices. The remains of its esteemed founder and first Sector Governor, Hal Orpheus, are borne in grand ceremony throughout the entire sector, his former flagship the Apocalypse-class Battleship Arica Dominus conducting a great tour of the region.
- The Silence of Leyak (976.M37) - The neighbouring Leyak Sector abruptly ceases all communication with the wider Imperium, resulting in the loss of billions of lives. An Ordo Xenos taskforce ventures into the now-silent sector and successfully returns but does not disclose what they witnessed there. Soon afterwards, the Segmentum Conclave of the Ordo Xenos drastically increases the military tithes of every world of the Orpheus Sector, raising new regiments for the Imperial Guard and Planetary Defence Forces, and requiring of the more industrialized worlds to heavily reinforce their orbital defences. In parallel, Battlefleet Orpheus is considerably reinforced, while all the worlds of the Veiled Region are declared forbidden under pain of death. As a further precautionary measure, several of the outlying worlds such as Altun are also declared Perdita.
- The Black Crusade of Von Mallas (Unknown Date.M38) - The heavy tithes resting on the Orpheus Sector had bred considerable discontent amongst the population, sometimes erupting into violent revolts and full-scale rebellions that were brutally repressed by the Adeptus Arbites and the local authorities. These tensions led to several purges of the civilian population which proved unsuccessful in stopping the rise of cultic activity. Preying on this spirit of discontent, demagogues and doomsayers soon have great influence within the populace. Originating from the Segmentum Pacificus, the Black Crusade of the Apostate Cardinal Von Mallas, more commonly known as "The False Saint" or "The Transgressor", soon spills over into the Orpheus Sector and its neighbours. The worlds of Epirus and Colkasth fully embrace the Heretic's creed and battle is joined. Those regiments raised in the wake of the Silence of Leyak are used to fight the Transgressor's expanding splinter-empire. Although the secessionists are ultimately defeated, the Agri-world of Epirus is devastated, the loss of its output causing food-shortages and famines across a great deal of the Orpheus Sector, breeding further discontent as worlds are ravaged by pestilence. The Penitentiary World of Morros Lachrymal is founded to process those Heretics who wish to repent for their crimes.
- The Rise of the Cult Celestarii (715.M38) - Born of the despair and bitterness caused by the recurring famines following the devastation of Epirus, a previously unknown cult rises in power, particularly amongst the wealthy and the nobility of the Orpheus Sector. Having taken the name of the Celestarii, the cult venerates the widespread xeno-archelogical sites across the sector as sacred, spreading the belief that the Imperial Creed is a lie and that the true gods of the galaxy, the Celestarii, would one day awaken from their eternal slumber and grant those that follow them eternal life, while bringing bloody death to those who oppose them. Little is known of the Celestarii's practices, although the cult is heavily persecuted by the Adeptus Arbites as well as the Ordo Hereticus. Investigations show that the cult acts more as a secret society, furthering the enrichment and power of their inner circle rather than trying to topple Imperial rule. Several clues indicate that the Celestarii carry out rituals of a cannibalistic nature.
- The Death of Tlaloc (889.M38) - In 889.M38 a patrol of Battlefleet Orpheus received garbled distress signals from the Agri-world of Tlaloc, at the very edge of the Drucillan Sub-sector. Upon the arrival of an Imperial fleet they find the world in ruins, its population decimated and every single recording device broken. The landing parties reported that the planet's settlements had been turned into an abattoir, every corpse seemingly ripped apart or having been flayed; yet despite the mutilation, it was clear there were not enough corpses to account for the entirety of Tlaloc's population. The Inquisition led an official investigation into the matter, which discovered that the ruin visited upon the world had been done in a matter of solar hours. Inquisitor Kussan of the Ordo Xenos came to the conclusion that the savage mutilations were tell-tale signs of Dark Eldar raiders or Eldar Corsairs. Other Inquisitors and several officers of the Orphean Admiralty, however, did not share this hypothesis and ordered the world quarantined by the Imperial Navy. This quarantine was still in effect at the time of the Orphean War.
- The Battle of the Gorgon Deep (160.M39) - With the help of the Revilers and the Red Seraphs Chapters of the Adeptus Astartes, Battlefleet Orpheus succeeded in stopping the rampage of a major Ork incursion at the sector's borders. Boarded by Terminator Squads that spearheaded the assault on the enemy flagship, the so-called Mega-Kroozer, the Orks were vanquished in a nineteen-week-long space battle. However, many of the smaller Ork ships scattered and found refuge in the asteroid belts, debris fields and gravitic vortexes that surrounded the Deluvian Sub-sector, soon to prove an almost constant thorn in the sector's side. Pirate and raider activity in the sector increased afterwards, putting further strain on Battlefleet Orpheus and the sector's commercial shipping.
- The Time of Revolt (860-903.M39) - Following a millennium of tension and crisis, the Orpheus Sector is put under new strain by Segmentum authorities when new troops are conscripted for the seemingly endless wars in the neighbouring Haxan Sector, where the Imperium was entangled on two fronts against the Eldar Slaughtervane Kabal and the Apostate Heptad. This ultimately proved too much to bear and the long-running tensions and rivalries between planets and ruling houses in the sector erupted first in bloody vendettas and assassination campaigns and then into open conflict. Sector-wide civil war broke out when the honour-clans of the Drucillan Cluster overthrew the local opposition and declared their formal secession from the Orpheus Sector. Drucilla Majoris quickly became a haven for all sorts of criminals and renegades but it also became a rallying point around which other Renegade factions could rally. The worlds of Apollyon and Selakhar fell to the sway of the Ruinous Powers, while on Amraphel the xenos mercenaries commissioned by Amraphel's parliament to attack its neighbours proved to be a splinter-web of the baleful Khrave, which preyed upon the world's elite. The infestation was discovered and expunged by an Adeptus Ministorum-led civil uprising.
- The Orphean War of Faith (903-922.M39) - With several worlds firmly on the grip of the vile servants of Chaos and the Orpheus Sector on the brink of tearing itself apart, an unexpected arrival led to the greatest military campaign since the Dark Marches Crusade. Guided by visions of the Holy Emperor Himself, Arch-Confessor Marduk of Helvamon had declared a war of faith to save the Orpheus Sector. His ramshackle fleet bore thousands of Imperial zealots, Imperial Guardsmen and militiamen as well as pilgrims, but more importantly, in the Arch-Confessor the fractious planetary governors and rulers found a figure behind which to rally. Soon, the Imperials launched a powerful counterattack, it fervor giving even the Daemons of Chaos pause. As the influence and presence of several warbands of Chaos Space Marines was confirmed, amongst which could be counted members of the Alpha Legion, the Night Lords and the Death Mongers, the Arch-Confessor called for help. His Imperial Crusade was soon reinforced by the entirety of the fleet-based Angels Revenant Chapter as well as the Adepta Sororitas in form of detachments from the Order of the Valorous Heart and the Order of the Black Sepulchre. Lastly, upon learning that daemons had been set loose, the Ordo Malleus also despatched a strike-force of its most fearful warriors, the legendary Grey Knights. With this mighty host, the Imperials reconquer their sector in a gruesome twenty-year-long campaign that would see a full fifth of the sector's population die.
- The Bane of Saint Marduk (921.M39) - Regarded as the last great battle of the Orphean War of Faith, the events of the Bane of Saint Marduk are shrouded in mystery, although later events confirmed the major role of the Maynarkh Dynasty in it. By 921.M39, the victorious forces of the Imperium had gathered to lay siege to the last stronghold in the hands of the Archenemy: the former Hive World of Colkasth that had been turned into a hellish fortress by the Warpsmith of the Death Mongers, fusing the bones and souls of the world's inhabitants into grotesque defensive structures or leaving them as mindless cannon-fodder. Daemons had been called from the Warp to further reinforce the defenders as the Imperial host around Arch-Confessor approached. While the first stage of the Imperial counter-invasion met with some measure of success, the contact with Marduk's army was soon lost, the last communications raising the alarm and calling for assistance. The first Imperial voidship to reach the system in response, an Adeptus Astartes Strike Cruiser belonging to the Angels Revenant, was met by two smaller yet extremely powerful ships of unknown provenance which succeeded in damaging the Intercessor. The Space Marines retaliated and destroyed one of their foes, upon which the second one disengaged, but the damage had been done. Its propulsion systems nearly destroyed, the Intercessor could only limp further into the system where it witnessed a terrific space battle occurring around Colkasth, presumably against the same unknown enemies the Astartes had just driven off. Upon its arrival, the Intercessor found only an orbital debris field and a ravaged world in the grip of a nuclear winter, yet the radiation did not match any form of weaponry known to man. Only a few survivors could be rescued and it soon appeared that Arch-Confessor Marduk himself had been slain. None the wiser, the Angels Revenant departed the system after having conducted emergency repairs. As the Arch-Confessor was soon beatified by the Ecclesiarchy, the world where he died became known as Saint Marduk's Bane and was recolonised after a ritual purification to ensure that the foul taint of Chaos did not linger there. The death of Saint Marduk marked the birth of the mysterious menace known as "The Sleepers of Orpheus," a tale soon to be forgotten.
- Establishment of Libethra (circa 010.M40) - Following the death of Saint Marduk and the eradication of the last Chaos-aligned forces within the sector, the Orphean War of Faith is deemed a great success. To commemorate the Saint's death, the colony world of Libethra, which the Saint had grown fond of, is converted into a Shrine World to harbour the war's honoured dead. The Space Marines Chapter of the Angels Revenant, until now a crusading Chapter, is given custody over Libethra, which considerably strengthens the sector's defences.
- The Death of Badrok (319.M40) - Unifying the descendants of the great Ork incursions of the 39th Millennium, Evil Sunz Warboss Badrok Gutgouga launches a WAAAGH! from the Shattered Deeps region against the Orpheus Sector. Confronted by the Orpheus Sector's defence forces and reinforced by regiments of the Imperial Guard, most notoriously armoured regiments from Koenig, the Orks are brought to battle. After seven solar months of gruelling battles, the Orks are finally encircled and defeated. Warboss Gutgouga is slain and his mortal remains are famously hanged from the spire of the Red Cathedral of Amraphel, marking the beginning of festivities across the entire Deluvian Sub-sector.
- The Great Severan War (580-591.M40) - As the border regions of the Segmentum Tempestus and the Ultima Segmentum are ravaged by this conflict of epic proportions, the Orpheus Sector contributes over thirty-nine million men and women to the Emperor's armies. To meet these requirements, the penitentiaries of Morros Lachrymal are converted from mining facilities to the raising and training of Penal Legions. Few of these regiments ever returned to the Orpheus Sector but their sacrifice is commemorated on Libethra by the raising of the great Basilica Severan.
- The Decapolis Conspiracy is Uncovered (619.M40) - Located to the galactic West of the Orpheus Sector, where it borders the Eurydice Sector, the Hive World of Decapolis has grown powerful and rich, mostly through trade with the neighbouring sector and the Mechanicum's Domain of Myre. Decapolis' wealth, population and economic output was such that it eclipsed even Amarah Prime itself, the ancestral seat of power and government of the Orpheus Sector. However, the ruling noble houses of Amarah jealously tried to remain in control, imposing ever-increasing tithes on Decapolis' merchant class in a vain effort to hinder its growth. Eventually, these tithes became so oppressing that Decapolis' ruling council, the Decrachs, both mercantile and military governors, decided to fight back. The Decrachs hatched a series of conspiracies and plans which revolved around the covert funding and arming of political dissidents on Amarah, heretical groups such as the Cult Celestarii and even narco-smuggling and contraband rings. As several officials were being eliminated in a targeted assassination campaign, these deaths prompted an Ordo Hereticus-led investigation. Upon interrogating captured Celestarii cultists, the full extent of the conspiracy is uncovered when the heavy weapons crates in their possession can be traced back to manufactoria on Decapolis. For the following nine standard years, the Inquisition conducts a series of systematic purges of Decapolis' ruling elite and sentenced them to death after extensive show trials. The harshness of these purges ultimately prevents outright civil war, but the even heavier tithes imposed by a now paranoid Amarah Prime upon the Hive World leads to vast civil resentment. The trust between the worlds of the Orpheus Sector is shattered and on Decapolis in particular the population's fealty is more enforced than earned.
- The Storm Tide (672-990.M41) - Line many of the other Imperial domains within the Segmentum Tempestus, the Orpheus Sector is increasingly plagued by a number of sudden, unpredictable, Warp-related torments such as aetheric disruptions and Warp squalls which make Warp-travel increasingly dangerous, even amongst established and well-travelled Warp-routes. The number of vessels lost in the Warp steadily rises and cultic activity increases in the sector with them. Many latent and established psykers are plagued by horrifying dreams and visions, featuring dead cities and the recurring image of a rising darkness, led by pale figures treading the dust of silent worlds and endless labyrinths. Only by the thorough efforts of both the Ordo Hereticus and Ordo Malleus, which battles ever more frequent incursions of psyker-daemons, is wider knowledge of these bleak portents of doom kept from the overall population. With the planets of the Orpheus Sector growing ever more isolated, the unity and security of the sector is only maintained by the tireless vigilance of the Angels Revenant and Battlefleet Orpheus, which constantly patrol the vicinity of the Hesod Nebula to hold off Eldar Corsairs that seek to prey on the more isolated worlds.
- The Howling Vortex (689.M41) - A localised but violent Warp Storm, designated the Howling Vortex, manifests in the Barren Stars region of the Capitoline Sub-sector, cutting all communications with the Penitentiary World of Morros. The fate of its thirteen million inhabitants remains unknown.
- The Kellerman Murders (744.M41) - On Amarah Prime, investigations led by the Adeptus Arbites reveal that a series of thefts and murders within the Kellerman Scholam are in fact a larger ploy of a Celestarii cult seeking to retrieve ancient xenos artefacts that are being stored and studied there. Cornered by the Adeptus Arbites, the Celestarii entrench themselves in the Scholam, which is successively ravaged by a fierce gun-battle and a conflagration which ravaged the Scholam's extensive collection. Several testimonies from eye-witnesses state that an unidentified figure stalked the ruins of the Scholam, seemingly unharmed by the blaze that had engulfed the building, apparently retrieving several artefacts before vanishing under mysterious circumstances.
- The Damnation of the Manticore (766.M41) - En route from Arcantis to Ribasu, the Geller Field of the Chartist freighter Manticore Agirus suffers several breaches while in the Warp and is overrun by daemons. The crew and their three thousand passengers' screams of agony plague astropathic communications in the entire Capitoline Sub-sector for several standard decades afterwards.
- The Warning of the Wayward Son (811.M41) - Several standard years after heading into the outer darkness, the exploration fleet of the minor Rogue Trader Caleb Gilderoy unexpectedly shows signs of returning to the Imperium's borders when one of the flotilla's Escort vessels, the void dromon Wayward Son, appears outside the defence perimeter of the Mechanicum outpost of Harrow Watch. As soon as contact is established, the Wayward Son states that it has been heavily damaged in battle with unidentified xenos, claiming that the Rogue Trader's flotilla has been entirely wiped out by an unknown "terror" from beyond the frontier. The Wayward Son desperately pleas for immediate sanctuary at the Adeptus Mechanicus base, but as it has no clearance to enter the Harrow Watch exclusion zone, its request is flatly refused by the Mechanicum officials. As the Wayward Son continues on its approach vector, despite explicit warnings not to do so, the voidship is destroyed by the Mechanicum's guns. What small portion remains of its wreckage is placed under quarantine for further investigation.
- The Shadow of the Beggar King (819.M41) - On the industrial world of Chemarium II, Iidris Hive succumbs to a seemingly contagious wave of madness and despair, resulting in the deaths of thousands of Imperial citizens either through suicide, murder or rampage. To further sabotage the world's manufacturing capabilities, many workers hurl themselves into the machines they were operating. Anarchy reigns within the streets and the collapse of society swiftly follows. Amongst this chaos, no doubt touched off by the Ruinous Powers, arose a previously unknown individual, Ranker Nonesuch, the so-called "Beggar King." Successfully eliminating or corrupting the Planetary Defence Forces, the Beggar King slaughters the planetary government and leads his hordes of insane followers to corrupt the other three remaining planets of the Chemarium System. Soon Chaos Cults such as the Endless Tide and the Crawling Darkness lead large scale terrorist campaigns and insurrections in those hive cities remaining loyal to the Imperium. Due to unstable Warp conditions, the Imperium is unable to marshal sufficient forces to expunge these Heretics and so an exclusion zone around the Chemarium System is established. As guerilla war slowly turns into a war of attrition, the outbreak is contained to the Chemarium System while the Inquisition mobilises its Storm Trooper regiments to deal with the threat.
- The Dying Stars (990.M41) - The Warp turbulence that has been plaguing the western marches of the Orpheus Sector since the Storm Tide three centuries before are inexplicably snuffed out by a powerful event in the Warp, leaving only the Howling Vortex. The shockwave causes tremors in the Warp and a great many vessels are thrown far off-course or destroyed, while throughout the entire sector, astropaths burn up or have their minds consumed by the psychic shockwave. Meanwhile, the deep range observation facilities of Harrow Watch report that the binary stars of the forbidden Caracol System at the edge of the Veiled Region inexplicably and unexpectedly went supernova, the event occurring roughly concurrently with the shockwave in the Warp. In the light of more recent events, it is safe to assume that these seemingly unrelated events were the first tell-tale signs of the awakening of the Maynarkh Dynasty.
- The Orphean War (3716.991.M41-0266.999.M41) - Finally awake, the Necrons of the Maynarkh Dynasty and its client-dynasties fall upon the ill-prepared Orpheus Sector, invading it both from the former Leyak Sector and through the Veiled Region, coming from the Outer Darkness. The first sign of this offensive of truly epic proportions was a desperate attempt of the Eldar Corsairs of the Hesod Nebula to flee, yet they clashed with the gathered might of Battlefleet Orpheus and the recently arrived Minotaurs Chapter of the Adeptus Astartes. It is only when the Mechanicum outpost of Harrow Watch is destroyed that the Imperium realises it has come under attack. The Drucillan Sub-sector is the first to fall entirely to the Necrons, and all contact is lost with the Angels Revenant on Libethra. Despite the rerouting of several reinforcements, the Necrons' advance cannot be stopped, merely slowed until it inexplicably stops of its own will, with a full half of the sector already in enemy hands. In the farflung Barren Stars region, the Necrons also captured and ravaged the vital Agri-world of Hydroghast, the Agri-world being the sole planet westwards of the sector's meridian to fall to the xenos. For a hundred solar days, the Necrons' advance halts, a welcome pause during which the sector's ruling Imperial Governor, Calibron Laan, musters all available military formations and fleets in defence of the sector capital world of Amarah Prime. This leads to the great Battle of Amarah, which leaves the sector's capital world in ruins and Battlefleet Orpheus shattered. Yet all is not lost. On the surface of Amarah Prime, the valiant regiments of the Death Korps of Krieg and the Necromundan Regiments successfully resist and push back the Necrons, even destroying one of the invaders' beachheads, while in space the Minotaurs' Chapter Master, the darkly famed Asterion Moloc, faces the dire leader of the Necrons in single battle and wounds him. The Necrons then retreat, but the losses are so catastrophic that it appears clear that the sector is doomed.
- The Orphean Decree (0266.999.M41) - Following the meagre victories and catastrophic losses of the Orphean War, the High Lords of Terra promulgate the Orphean Decree, which disbands the Orpheus Sector by Act of Discorporation. For all intent and purposes, the Orpheus Sector is no more. What Imperial naval and military forces remain are engaged in the Orphean Salvation Campaign, fighting desperate rearguard actions to hold off the Necron advance. Using the same scorched earth tactics as against the Tyranids, the worlds remaining under Imperial control are to be evacuated and stripped of every useful resource before being subjected to Exterminatus. The neighbouring Eurydice Sector becomes the new frontline and outer border of the Imperium of Mankind, its worlds and armies fortifying in case the Necrons intend to follow the retreating Imperials.
Astrography of the Orpheus Sector
Notable Celestial Phenomena
- Hesod Nebula - The Hesod Nebula encompasses large parts of the Orpheus Sector's northern approaches. It has long served as a safe haven for Dark Eldar corsairs and pirates which Battlefleet Orpheus had thus far failed to eliminate. This would change with the beginning of the Orphean War as the raiders either perished at the hands of the Necrons or were forced out of hiding into the guns of the Imperial Navy and the Minotaurs Chapter of the Adeptus Astartes.
- Howling Vortex - The Howling Vortex is a small-magnitude but extremely fierce Warp Storm that manifested itself in 689.M41, engulfing the world of Morros and cutting all contact with it since that day. The Howling Vortex effectively reduced the Barren Stars region to just the Hydroghast System.
- Shattered Deeps - Located at the Southern edge of the Orpheus Sector, the Shattered Deeps form a Warp/realspace interface akin to the famous Maelstrom or the Eye of Terror although of much smaller magnitude. The anomaly itself has drawn a tremendous number of asteroids to it, which have become the refuge of several klans of space-faring Orks.
- Veiled Region - Located to the galactic Southwest of the sector capital world, the Veiled Region marks the Segmentum Tempestus' outer border, a final obstacle before the immensity of the Outer Darkness. The region carries its name well as dense nebulas, great debris fields and turbulent gravitic forces make navigation utterly impossible and even "veil" the light of the few existing stars left that are only orbited by Dead Worlds. It would seem that at least a portion of the Necron invader came from the Outer Darkness and thus passed through this region of space to reach the Orpheus Sector. How such a feat was possible remains entirely unknown.
Notable Sub-sectors and Regions
The size of the Orpheus Sector is such that to ease its ponderous administration, the sector was divided into three primary Sub-sectors and several independent administrative regions.
- Capitoline Sub-sector - As its name indicates the Capitoline Sub-sector is the most important division of the entire sector, home to both the sector capital world of Amarah Prime and the populous worlds of the Arcantis Cluster. These heavily industrialised and populated worlds rely heavily on imports from the semi-autonomous domain of the Barren Stars and the Agri-world of Hydroghast that lies therein to survive.
- Deluvian Sub-sector - The Deluvian Sub-sector lies to the galactic Southeast of the Capitoline Sub-sector and is perhaps the second most important region of the Orpheus Sector. Following the Orphean War, the Deluvian Sub-sector has suffered less than the rest of the region and still defies the invaders.
- Drucillan Sub-sector - The worlds of the Drucillan Sub-sector were by far the least advanced of the Orpheus Sector, yet suffered perhaps the worst during the eons as the outlying worlds fell one after the other to the baleful presence of xenos species, servants of the Ruinous Powers or others perils. Being located to the galactic South-Southwest of Amarah Prime where the Orpheus Sector touches the lost Leyak Sector, the Drucillan Sub-sector was the first to fall before the Necrons of the Maynarkh Dynasty and is considered utterly lost by the Imperium's tacticians.
- Barren Stars - Located to the galactic West of the Capitoline Sub-sector to which it is attached, the Barren Stars are -- as their name indicates -- a desolate streak of space, distant enough from the sector's capital world to warrant some form of political autonomy. The Barren Stars is made up of only two worlds of any strategic importance, the Agri-world of Hydroghast, and the Penal World of Morros Lachrymal.
- Cold Veil - The Cold Veil is an independent administrative region within the Orpheus Sector. It is situated to the galactic Northeast of the Drucillan Sub-sector, to which it is closest, but also maintains close ties to the Capitoline Sub-sector where most of its stable Warp routes lead. The Cold Veil is dominated by the Adeptus Astartes homeworld of Libethra which was established along the route taken by Saint Marduk during the 39th Millennium, the so-called Orphean Pilgrimage.
Notable Exclusion Zones
Subjected to many strange Warp phenomena, the Orpheus Sector counts many worlds upon which the Inquisition has placed a ban and where no citizen of the Imperium should dwell. The true reasons for this ban are often kept secret. Most tellingly, these prohibited worlds are all located on the exterior of the sector, close to the Segmentum's borders with the Outer Darkness. In this there is only one notable exception, the Chemarium Exclusion Zone. The worlds of the Chemarium System had simultaneously entered a state of open revolt against Imperial rule and had been cordoned off while awaiting sufficient reinforcements to pacify those worlds which had fallen to the sway of the Forces of Chaos. Those reinforcements were hastily redeployed at the outset of the Orphean War.
- Altun (Dead World)
- Carocol (Dead World)
- Chemarium (Industrial Worlds) - Located in the Deluvian Sub-sector, Chemarium I - IV were heavily industrialised worlds whose output principally went to Amarah Prime itself, the hive cities of Decapolis and the Forge World of Myre. On Chemarium III, the civilian population had risen against the rule of the Emperor under the leadership of the so-called "Beggar King," warranting a blockade of the entire star system which became known as the Chemarium Exclusion Zone. Although the baleful influence of the Ruinous Powers has been confirmed, it is unknown how the taint spread so long unnoticed.
- Cutlar (Dead World)
- Nightshard (Prohibited World)- Located at the very edge of the Veiled Region, the world of Nightshard is a scientific enigma and has therefor been declared Prohibita by the sector's Conclave of Ordos. Nightshard's celestial mass is highly anomalous for a planet this size.
- Tlaloc (Agri-world) - Tlaloc is an ill-fated Agri-world established on the southern borders of the Orpheus Sector, where it touches the now-lost Leyak Sector. When the first Imperial colonisation fleet bound for Tlaloc mysteriously vanished, nobody truly suspected the horrible fate that would be visited on this world in the last decades of the 800s of M38. Referred to as "the Death of Tlaloc" in several open records, the world's population was decimated, and not a single intact corpse was found amongst the ruins of the planet. Official investigations led by Inquisitor Kussan of the Ordo Xenos put the blame on Eldar Corsairs, but in the wake of the Orphean War it would seem that far older, darker forces were at work on Tlaloc. Nevertheless, since 889.M38 and these mysterious events, Tlaloc has remained in permanent quarantine.
- Uxmal (Death World)
Principal Worlds of the Orpheus Sector
- Amarah Prime (Hive World) - Second planet of the Amarah System, Amarah Prime is a teeming Hive World of old and noble provenance. As the oldest human settlement within the entire Orpheus Sector, having been found in the distant 30th Millennium by the legendary Rogue Trader Lady Arica Orpheus, Amarah had known a first existence as a minor Imperial outpost before being destroyed in the wake of the Horus Heresy. When the Imperium reclaimed the Orpheus Sector during the Dark Marches Crusade, Amarah Prime was naturally chosen as the sector's capital world, a position it has kept over the next four standard millennia. As well as being a Fortress Imperialis in its own right, Amarah also serves as Battlefleet Orpheus' principal fleet anchorage, making it the political and military heart of the Orpheus Sector. Despite the power it harboured, Amarah was devastated in the last major battle of the Orphean War, the famed Battle of Amarah. Like the two other Hive Worlds in this system, Amarah Prime is now reduced to a broken landscape of toppled tower, broken bastions and ravaged hab blocks, the heavy fighting having left the world an ash-shrouded wasteland, partly covered in radioactive fallout and burning skies.
- Amraphel (Civilised World) - Well on its way to becoming a Hive World of its own, the planet of Amraphel was located at the heart of the Deluvian Sub-sector. Amraphel is largely regarded as the most influential world of the Deluvian Sub-sector, its pious population having toiled for generations to erect one of the architectural wonders of the Orpheus Sector, the Red Cathedral from which most notoriously the remains of the Ork Warboss Badrok Gutgouga were hung in 319.M40. Amraphel was one of the few worlds having been evacuated before the arrival of the front lines to its world and was thus spared the multiple atrocities that happened elsewhere in the sector. After the proclamation of the Orphean Decree, Amraphel was abandoned, like much of the Deluvian Sub-sector and subjected to an Exterminatus by the Imperial Navy.
- Apollyon (Inquisitorial Fortress World) - Located in the Capitoline Sub-sector, close to the sector's seat of power on Amarah Prime, lies Apollyon, a former Hive World which fell to the dark promises and temptations of the Ruinous Powers in the last centuries of the 39th Millennium. Following its reconquest during the great Orphean War of Faith and thorough purges, the planet was given over to the Inquisition which established a more permanent base. The three great Ordos each established their presence on the planet, acting in concert as the Conclave Orpheus, but in truth it was the Ordo Malleus which reigned supreme, its representative Lord Inquisitor Hiram Ntshona having the ears of the sector's Imperial Governor, Calibron Laan, since the Chemarium Insurrections and the rise of the Beggar-King. Apollyon was the first world that successfully raised the alarm upon being attacked by the Necrons, a lone Inquisitorial ship, burnt black from stem to stern, having managed to escape the doomed system. The planet itself was irremediably shattered when the Necrons used the planet's moon, Elohiem Mortua, as a gigantic projectile to destroy its continents.
- Ayrith (Feudal World) - Close neighbour to the more populous and advanced world of Drucilla Majoris, Ayrith was one of the very first worlds to fall before the Necrons, the immortal legions of the xenos making short work of the technologically vastly inferior humans.
- Arcantis (Civilised World) - West of the Amarah System lies the Arcantis Cluster, named such for the Civilised World of Arcantis that dominates it economically and politically. The worlds of the Arcantis Cluster had always been spared by the greater catastrophes of the Orpheus Sector's tumultuous history, which left them ill-prepared for the onslaught the Maynarkh would bring. After the great Battle of Amarah, the front lines quickly progressed to Arcantis, where the Imperium's defenders would first encounter the so called "Walking Dead" the stitched-together and Scarab-controlled remains of the Necrons' former victims.
- C'syn'ad (Relic World) - C'syn'ad is located at the heart of the Deluvian Sub-sector in the galactic South of the Orpheus Sector. The world itself harbours great ruins of an ancient civilisation and has not been fully colonised by the Imperium. Some scavengers and Explorators seeking valuable archeotech sometimes venture to the surface, but the world's true importance lies in its orbit, for C'syn'ad harbours an immense orbital station which serves as a secondary base for Battlefleet Orpheus against the Ork raiders of the Shattered Deeps. The orbital also harbours the Orpheus Sector's greatest Astropathic Choir, capable of transmitting and receiving messages even from the Segmentum Solar. C'syn'ad was abandoned as part of the Imperium's retreat from the Orpheus Sector and subjected to Exterminatus.
- Chemarium I-IV (Industrial Worlds) - The worlds of the Chemarium System belonged to the Deluvian Sub-sector, and were all heavily industrialised worlds whose centuries of polluting activities had ravaged their existing biospheres and damaged the environment so heavily that its citizens lived in great proto-hive cities and only ventured outside wearing rebreather masks and protective gear. Each of the worlds of the Chemarium System boasted its own form of toxicity, from the acidic swamps of Chemarium III, to the ash-shrouded wastes of Chemarium IV. It is believed that the output of these four worlds combined easily matched the industrial output of a fully-fledged Forge World. Shortly before the outburst of the Orphean War, the civilian population of Chemarium III had been corrupted by the vile promises of Chaos and risen against the rule of the Divine Emperor. Amongst the teeming multitude emerged a leader, the so-called "Beggar King," who successfully coordinated uprisings on the other worlds of the Chemarium Systems, laying those cities that did not fell to him to siege. Due to the vagaries of the Warp, sector authorities were unable to ship sufficient men, ammunition and wargear to this new warzone, which warranted the creation of the Chemarium Exclusion Zone, a security cordon and blockade destined to hem the Heretics in the Chemarium System until such time as more regiments could be mobilised. These reserves would then constitute the first wave of Imperial reinforcements to counter the expansion of the Maynarkh. Throughout the campaign that would follow, Chemarium was largely ignored by the Imperials, who resolved to leave the Heretics' extermination to the Necrons. Seemingly abandoned by their Imperial masters, the resisting cities soon turned to the Chaos Gods to deliver them from these invading xenos. The war between these two factions seems to be ongoing.
- Decapolis (Hive World) - Although it harbours more people and its manufacturing capacities surpass those of Amarah Prime, Decapolis has always stood in the shadow of the sector's capital world. This rivalry ultimately led to the great Decapolis Conspiracy, which tried to wrestle dominion of the Capitoline Sub-sector -- and indeed the entire Orpheus Sector -- from Amarah. This plot, however, prompted the ire of the Emperor's Inquisition, which conducted heavy purges on the world after obtaining proof that Decpolis' ruling council of Decrachs was in league with xenos and Chaos-aligned cults, which it not only funded, but also equipped with weapons. The Inquisition's heavy hand, which condemned the Decrachs to death after extensive show-trials and sent millions of its inhabitants into the penitentiary colonies of Morros, bred considerable resentment within the population, resentment which only grew after the paranoid Governor of Amarah, Calibron Laan, imposed even heavier tithes on their world. Therefore, many believe that the situation on Decapolis was a new crisis in the making interrupted only by the Necrons' invasion. Decapolis was spared the greater devastation of the sector, its population and industrial might having mostly been relocated by the time the front lines reached the once great and powerful Hive World. Like the other major worlds of the sector, Decapolis was scourged by Exterminatus.
- Drucilla Majoris (Imperial World) - As its name indicates, Drucilla Majoris is the major and dominant world within the Drucillan Sub-sector, located itself in the galactic Southwest of the Orpheus Sector, on the border with the former Leyak Sector. Considered by many a mere frontier realm, Drucilla Majoris harbours many towering and extensive complexes of xenos ruins, which seemingly indicates that in the distant past, Drucilla Majoris was once part of another stellar empire. These ruins are held in high esteem by those seditious elements known to belong to the Cult Celestarii, who are believed to consider Drucilla as some sort of holy ground for their deluded faith. The entire Drucillan Sub-sector was quickly overwhelmed and seized by the Necrons in the opening weeks of the Orphean War.
- Epirus (Agri-World) - Epirus is the Capitoline Sub-sector's most important provender of food, feeding such populous worlds as Amarah Prime and Ribasu.
- Gorgon Quintus (Death World) - Located in the extreme East of the Deluvian Sub-sector, close to its border with the Eurydice Sector, Gorgon Quintus is a Death World which also serves as a muster station for the Imperial Guard and other Imperial forces in their delaying effort covering the Imperial retreat from the Orpheus Sector.
- Harrow Watch (Adeptus Mechanicus World) - Harrow Watch is located to the galactic Northwest of the Orpheus Sector, beyond the pirate-infested region of the Hesod Nebula. It acts as a solitary vigil on the Imperium's borders with the outer darkness. Since the sector's creation, Harrow Watch was given over to the total control of the Adeptus Mechanicus, which quickly established it as a heavily-defended observation outpost to survey the exterior borders as well as the prohibited binary star system of Caracol through their powerful telescopes and Augurs. In these duties, the outpost of Harrow Watch would singularly fail, recording and transmitting the destruction of the Caracol System, but failing to discover the approaching Necron invasion forces, or even relay the warnings of the Wayward Son back in 811.M41, a standard century and a half before the Orphean War would lead to the dissolution of the sector. Like most exterior worlds, Harrow Watch was submerged by the Necrons in the very first solar hours of the conflict. The planet's demise was so swift that not even the alarm was raised.
- Hydroghast (Agri-World, Ocean World) - Located within the Barren Stars, Hydroghast is an exceptional world. It owes its existence to the influence of no less than three suns, which contributed to the creation of a solid planet the size of a more commonplace gas giant. Yet the gravitational forces of the three suns cancel each other out so perfectly that human life was sustainable instead of being immediately crushed by the world's gravity. Hydroghast is an Ocean World whose oceans are hundreds of kilometres deep and whose only landmasses are swamp-riven and fen-covered polar continents where the Imperium has erected several reinforced agri-stations to harness the oceans' resources. These outposts of civilisation are often separated by heavy monsoon rains and storms. Hydroghast's aquacultural output is vital to the Orpheus Sector as it feeds every Hive World of the sector, and its loss early on in the Orphean War was a terrible blow to the Imperial war-effort. How this happened remains a mystery, as Hydroghast was located far from the front lines, but what information could be gathered seems to indicate that the Necrons of the Maynarkh Dynasty rose from the oceans and swamps themselves to attack the Imperial colonists.
- Khesd (Feudal World) - A Feudal World close to Amarah Prime where the resources of several minor colonies and outposts were gathered before being shipped to Amarah or Myre.
- Libethra (Shrine World, Adeptus Astartes Homeworld) - Transformed into a Shrine World in the wake of the great Orphean War of Faith and the dramatic events of the Bane of Saint Marduk, Libethra was a world of towering beauty whose vast marble mausoleum complexes harboured the Orpheus Sector's glorious dead. It was on Libethra that the Great Basilica Severan was erected to commemorate the blood shed by the Orphean Regiments of the Imperial Guard in the Great Severan War. As homeworld to the Adeptus Astartes Chapter of the Angels Revenant, the world's second great marvel was the Chapter's fortress-monastery, its skies filled with the ballet of the Chapter's fleet movements, for the Angels Revenant regarded themselves justly as the protectors of the entire Orphean Pilgrimage and indeed the Orpheus Sector. During the Orphean War, contact was soon lost with Libethra, and the Chapter's fate was unknown for many solar months. From what could be assessed, the Angels Revenant made the Necrons fight for every step they took and despite initial successes, were soon forced into the defence of their homeworld. Confronted with such fierce resistance, the Necrons resolved to break through the planet's crust and have its molten core eradicate the Angels Revenant rather than risk the loss of too many of its ground forces.
- Lysmarchus (Fortress World) - Located in the Deluvian Sub-sector, Lysmarchus was the battlefield on which Warboss Badrok Gutgouga was defeated in 319.M40.
- Midwinter (Industrial World) - Close neighbour to Amarah Prime and location of Battlefleet Orpheus' principal naval shipyards. The star system had been protected by a Ramilies-class Starfort designated Fortress Tarris which was quickly overwhelmed by Necron forces, its crew powerless against the killing automatons teleporting directly into the bowels of their stronghold.
- Morros (Penal World) - More commonly called Morros Lachrymal, for it follows the tenets of the Lachrymal Pattern for penitentiary worlds, the world of Morros was initially founded as a simple mining colony and would only be transformed into a prison-colony in the 39th Millennium, following the Black Crusade of Von Mallas. On Morros, these penitents and convicts would toil hard to feed the Orpheus Sector's industrial appetite, and it would only be five hundred standard years later that the penitentiaries of Morros would be converted to the training of Penal Legions, the Imperium needing more fighting men to prosecute the Great Severan War. Later in the 41st Millennium, Morros Lachrymal's population swelled considerably due to the millions condemned in the wake of the Decapolis Conspiracy, when the Ordo Hereticus sentenced a sizeable portion of that Hive World's population to live out their lives on Morros. The planet's ultimate fate remains unknown, as since 689.M41 all contact with Morros has been lost due to the sudden manifestation of the Warp Storm known as the Howling Vortex.
- Myre (Forge World) - The Forge World of Myre is the single most important domain of the Adeptus Mechanicus within the former Orpheus Sector. Myre's production lines were at least partly destined to provide the needs of Battlefleet Orpheus, and include a great deal of aircraft such as the Avenger Strike Fighter. By the time of the Orphean War, Myre was a fully-fledged Forge World whose strategic importance was such, that as part of the Orphean Decree, Myre's entire population and infrastructure was relocated in the Jirgath System and countless lives have been spent to prevent the Necrons from interfering in this delicate matter.
- Pallasite (Frontier World) - Located in the Drucillan Sub-sector, Pallasite is the closest neighbour to the Dead World of Altun and has since then been placed under quarantine. It is widely believed that Pallasite was the first world to be taken by the Necrons' second front.
- Patara (Feral World) - Located at the other end of the Orphean Pilgrimage, Patara breeds a sturdy stock of humans, which explains why the Angels Revenant have been using this world as their primary recruitment location.
- Ribasu (Hive World) - Ribasu was once a teeming Hive World, but had entered a steady phase of decline well before the events of the Orphean War. The Necron invasion only hastened the world's ultimate death, but the great hive cities of Ribasu saw many fiercely-fought battles.
- Selakhar (Frontier World)
- Saint Marduk’s Bane (Civilised World) - Formerly known by the name of Colkasth, a teeming Hive World that became corrupted by Chaos and would also become the base of operations for the justly feared Death Mongers warband of Chaos Space Marines, the world of Saint Marduk's Bane owes its current name to the tragic destiny that befell Arch-Confessor Marduk of Helvamon, hero of the Orphean War of Faith and saviour of the entire Orpheus Sector. Following its devastation in 921.M39 by an unknown but powerful foe now believed to be the Necrons, the black-cindered, ash-covered world was renamed Saint Marduk's Bane. Due to this close affiliation with the Saint, the world quickly began to attract new colonists and became an established Imperial world in the space of a few centuries. Close to the new fortress-monastery of the Angels Revenant, the world was well-protected, but would fail to defend itself before the Necron onslaught.
- Thamyris (Abandoned World) - Thamyris is an arid world, covered in shifting sands which contain valuable and rare isotopes which had motivated several mining expeditions to be despatched to this distant world of the Deluvian Sub-sector. Several of these expeditions ended in disaster or failed to return at all, which soon gained Thamyris a privileged place in the sector's darkest legends. By that time, Thamyris was well on its way to becoming an Industrial World, but as expeditions continued to vanish or returned empty-handed, the planet was soon abandoned. No one made the link with the great xenos obelisks and other ruins found in the deserts until the Maynarkh attacked. Suddenly, the distant world became one of strategic importance, and offered the Imperium a target for counterattack. If Thamyris was indeed a Necron Tomb World emerging from slumber, or a link in some other unfathomable plan of the enemy, no one can truly know, but Segmentum authorities have sanctioned the use of Exterminatus-class weaponry.
- Tlaloc (Dead World) - Cursed Tlaloc is another darkly famed world within the Orpheus Sector. Located in the extreme South of the sector, Tlaloc was due to become an Agri-world, however the first colonisation fleet despatched to this planet was lost in the Warp in 817.M36 and it would be only thirty standard years later that the world would ultimately be colonised, albeit by a much smaller contingent of Imperial colonists. In 889.M38, a patrol of Battlefleet Orpheus received garbled distress signals from the Agri-world of Tlaloc, only to find the world in ruins, its population vanished and every single recording device broken. The landing parties reported that the townships and cities had been turned into an abattoir, every corpse seemingly ripped apart, cut into ribbons or having been flayed. Ordo Xenos-led investigations came to the conclusion that the mutilations and savagery of it were tell-tale signs of Dark Eldar raiders or Eldar Kabalite Corsairs, but it seems evident now that the Necrons were behind the death of Tlaloc. No one has set foot on Tlaloc for over two standard millennia.
- Imperial Armour Volume Twelve: the Fall of Orpheus, pp. 12-38, 59-62, 72-75