The Legio Tempestus ("Stormlords") is one of the oldest and most esteemed Titan Legions of the Collegia Titanica, one of the military arms of the Adeptus Mechanicus. One third of the fabled "Triad Ferrum Morgulus," the Legio Tempestus (or Tempestor as some later accounts termed the Order) was founded alongside the Legio Mortis and Legio Ignatum in the distant Age of Strife on Mars.
During the Great Crusade the Legion fought for solar decades at the leading edge of the Imperium's expansion alongside the most celebrated of the Legiones Astartes. Countless worlds were brought to Imperial Compliance and numerous xenos empires cast down for which the Legion became well known, earning it the epithet "Stormlords."
Later, however, the loyalties of the Legio Tempestus would be cast in doubt and the shadows of treachery attain its name. For while their lord and his retainers fought valiantly against the Traitors during the Martian civil war during the opening days of the Horus Heresy, others in their ranks, who had spent years on the dark frontier fighting under the flag of Horus, would be counted amongst the most dedicated of the Warmaster's treacherous forces during the wars of the Heresy.
During the Horus Heresy, there were major elements within the Legion that declared their allegiance for the Warmaster Horus and his cause. Many elements, including those left on Mars during the Schism of Mars, and those elements of the Legion serving further afield, refused to submit and share the betrayal of the traitorous senior Princeps Maximus Karania, who took control of the Legion following the death of its former lord.
Following the end of the Heresy, the Legio Tempestus made their homeworld the Forge World of Orestes in the Segmentum Pacificus. The Orestean faction of the Mechanicus is noted for its theological distinction between the notions of the Omnissiah and the Emperor, a belief that was shared by the personnel of the Legio Tempestus.
The Legio Tempestus is a Titan Legion of the Collegia Titanica, its towering God-engines counted amongst the mightiest and most accomplished of the Emperor's Crusading hosts in the years before the Horus Heresy. One third of the fabled "Triad Ferrum Morgulus," the Legio Tempestus was founded alongside the Legio Mortis and Legio Ignatum in the distant Age of Strife on Mars.
Throughout the blood-soaked insanity of that age, the Legio Tempestus stood firm against all foes, from machine-mutant abominations rising from the waste-strewn oxide deserts to rival Titan Orders marching from their own strongholds to battle. Their home fortress, cut from the red basalt of Ascraeus Mons, in the Ascraeus Chasmataone, one of the mightiest of Mars' many volcanoes, remained inviolate. Concentric rings of impregnable fortifications rose atop each of the solidified lava ridges surrounding the fortress, whilst below, Tempestus God-engines walked from towering armoured gates and scoured the surrounding plains of the tides of degenerate tech-savagery that broke continuously against them.
Much of the anarchy that befell Mars during the long Age of Strife is lost to history or sealed away in forgotten data-crypts beneath the industrial wastes -- with the treachery revealed in the opening years of the 31st Millennium, few can imagine a complete history will ever be composed. It is known, however, that the region claimed and defended by the Legio Tempestus bordered that of the Legio Mortis -- the Death's Heads -- and on countless occasions the two Orders came to blows over territorial rights and access to the priceless caches of archaeotech to be found beneath the rust runes of the Tharsis region.
Their mighty fortress was located in close proximity to Ascraeus Mons, at Pavonis Mons. The engines of these ancient Orders battled across the oxide deserts until, at length, the region was divided by the Tempest Line. To cross this line in the red sand was to unequivocally declare war, an act that the Legio Mortis initiated on many more occasions than Tempestus if rumour was to be believed, and though both Orders shared a common enemy in the Cy-Carnivora and other phantasms of Old Night that plagued Mars throughout the age, a deep and mutual loathing developed between them that would later bear bitter fruit.
The Great Crusade
With the coming of the Emperor to the Red Planet and the signing of the Treaty of Mars, the Legio Tempestus took its place in the glorious hosts of Mankind's all-conquering armies. Tempestus engines walked upon worlds the length and breadth of the ever expanding Imperium, serving alongside some of the most celebrated forces of the Great Crusade. Individual maniples were detached to Mechanicum Explorator fleets and Rogue Trader Militant pathfinder squadrons, but the bulk of the Legion's most celebrated battle honours were earned during service with the 12th Expeditionary Fleet, in what some historians later dubbed the "Long March to Ultramar."
Later on, when the Lord of Ultramar, the Primarch Roboute Guilliman, took personal command of the 12th Expeditionary Fleet, the Tempestus played a pivotal role in the arduous wars of the Epsiloid Binary Cluster. It was during this epic conflict that the Legion's master, Princeps Senioris Indias Cavalerio, earned the title "Stormlord," a name soon used by allied Imperial soldiers to refer to the entire Legion and was thought to echo ancient myths.
The term was appropriate, for the Stormlords had proven themselves masters of planetary assault under enemy fire in hostile circumstances many other princeps would never have allowed their own forces to be risked at such hazard. Cradled in the shielded holds of the very heaviest classes of drop transport constructed in the orbital void-factories on Mars, the Legion's brutal descents into battle, shrouded by the fire and storm-turbulence of the drop ship's almost suicidal trajectories, became legendary. They caused atmospheres to burn and made such ruin of the skies that on some worlds the storms they caused would not fully abate for years. Where the Stormlords walked, cities were shattered and battlefields were swept of the foe by a blistering hail of ordnance.
After an abated campaign of six solar decades on the forefront of the Great Crusade, the Legio Tempestus suffered heavy losses -- including Victorix Magna, the Warlord Titan of the Stormlord himself -- and needed time to regroup and rearm or risk destruction. Having claimed warden right over key worlds in the Estaban and Orestes Systems, the Legion's master, Cavalerio, returned to Mars with those of his Legion's god-engines in most need of repair and refit, entrusting command of the remainder of a reorganised demi-Legion to his lieutenant, Princeps Maximus Karania.
Thus would begin a chain of events that would lead to a growing rift, more a development of circumstance and distance than any actual acrimony or malice, between the two halves of the Legio Tempestus. In the years that followed, two separate commands developed, with little direct contact between them, each being supplied separately and fighting their wars apart under the light of far distant stars. The Martian Tempestus began to be deployed as a heavy reserve, called to battle from their base on Mars to re-enforce the line in the most precarious war zones and to punish rebellious worlds before swiftly returning to their home, while Karania's command would pass from the order of battle of one far-flung Expeditionary fleet to another, never seeing the light of Sol.
The events that unfolded on Mars decades after Cavalerio's return to the Red Planet, formed a crucial fulcrum in the Warmaster's conspiracy to unmake that which the Emperor had built during the Great Crusade. During the 31st Millennium the climate on Mars was one of great discontent. There were tense relations between the various Techno-Magi with sporadic outbreaks of espionage and violence being committed amongst the forge cities that represented the primary sociopolitical units of Mars. There were even unconfirmed suspicions that the Titan Legions had already secretly chosen sides in case of a potential civil conflict.
Princeps Senioris Cavalerio sought to keep his Legion free from the insidious poison of the Mechanicus' politicking. He believed that the Titan Legions should remain true to their warrior ideals and not be instruments of the Magi's political will, and serve only the interests of the Imperium of Man itself. During the Great Crusade the Legio Tempestus supported Primarch Guilliman's Ultramarines Legion. Shortly before the outbreak of the Horus Heresy, the Legion took part in the Epsiloid Binary Cluster Campaign, during which the Titan of Princeps Cavalerio was damaged, forcing him to leave the bulk of the Legio Tempestus under the command of Princeps Maximus Karania and join the detachment of war engines headed to Mars for repairs. Princeps Cavalerio was scheduled to remain on Mars until all of his Titans were fit to return to combat.
When the Schism of Mars began during the opening days of the Horus Heresy the Legio Mortis forces, led by Princeps Camulos in the towering Imperator-class Titan Aquila Ignis, moved to threaten the Legio Tempestus stronghold at Ascraeus Mons. The Death's Heads trespassed on Legio Tempestus territory, violating an agreement signed between the two rival Titan Legions several centuries prior. Although the Legio Tempestus had the right to open fire on the offending war engines, Princeps Cavalerio dared not do so, as his forces stood no chance against the awesome power of the Imperator Titan, and he was also unwilling to be the one to start a shooting war between brother Titans on the surface of Mars.
A stand off between the two forces occurred in front of the Ascraeus Chasmata, and although not a single shot had been fired, the Legio Tempestus war engines were struck by a scrapcode (computer virus) attack that caused the death of a number of Legio Tempestus personnel aboard the Titans, as well as destroyed Princeps Cavalerio's Titan, the Victorix Magna. Following this assault, the Legio Mortis retreated from Legio Tempestus territory. As a result of the death of his Titan, Cavalerio had to be interred in an amniotic tank, which required a period of psychological adjustment to become comfortable with his new existence. During this time, Cavalerio was deemed unfit to command the Legion, and Princeps Kel Sharaq assumed his duties as acting Princeps Senioris of the Legio Tempestus on Mars.
Princeps Cavalerio slowly recovered while the conflict on the surface of Mars escalated, and although Princeps Sharaq received numerous petitions from Mechanicus forge cities asking the Legio Tempestus to intervene, he acceded to none, as he believed that such an order should come only from the Stormlord himself. Facing the Legion's gravest crisis in its long and glorious history, Princeps Senioris Cavalerio felt that warriors of honour and courage should not stand idly by in such times, but act. He assembled his Princeps and proclaimed to them that the Legio Tempestus would go to war, with him in command of the Legion's first god-machine, the Deus Tempestus.
The Legio Tempestus sallied forth in support of Magma City, a Loyalist forge that stood in defiance of the newly imposed order of the corrupt Fabricator General Kelbor-Hal and his Dark Mechanicus co-conspirators. The forces of the Legio Tempestus stood firm in the face of aggression in the defence of their allies, though they knew they would find their inevitable doom at the hands of their hated rivals in the Legio Mortis. The Legio Tempestus was overwhelmed by the superior numbers and firepower of their rivals. Despite the odds, the Stormlord valiantly led his Legion in the destruction of the Death's Heads' lesser war machines, only to face his own destruction, along with the remainder of his own war engines, at the hands of the Imperator-class Titan Aquila Ignis.
The heroic deeds performed in that final battle will never be fully honoured, for most who witnessed them perished themselves as Magma City sunk into the Red Planet's savage fiery mantle. After the tragedy on Mars, there remained only a scattered handful of Loyalist Legio Tempestus Titan maniples and detachments who had not been present on the Red Planet, free and in the Imperium's service, but left leaderless and bereft, and soon to face the double blow of the news that their distant brothers had themselves turned Traitor.
While leading his own division of the Legio Tempestus, Karania proved himself a strategist whose cunning served as a formidable force multiplier and elevated the Legio to the highest tiers of the Warmaster's servants. This rise in favour, however, was ever checked, for its oldest foe, the Legio Mortis, remained of all the Traitor Titan Legions always first in Horus' service. Despite their common cause in the ranks of the arch-Traitor, Tempestus and Mortis, long rivals, slowly became bitterest enemies even as they fought alongside each other, a diametrical opposition that would at length become horribly evident as the unspeakable powers each had sworn themselves to exerted their hideous influence.
There are no records of the Legio Tempestus engaging in any further actions during the remainder of the Horus Heresy, though it is presumed they continued to fight on. At some point in its later history, the traitorous elements of the Legio Tempestus (now referred to as the Legio Tempestor) were present during the Battle of Terra, but when the Warmaster fell, they were driven towards the Eye of Terror along with the rest of the Traitor Legions during the era known as the Great Scouring. There they remain, trapped in servitude to the Chaos Gods, fighting the Long War against the "Corpse Emperor" that began ten millennia before.
The Legio Tempestor 's current whereabouts are unknown. The Loyalist Legio Tempestus was later relocated to the Forge World of Orestes, located in the Segmentum Pacificus. Its most recent action was participation in the Sabbat Worlds Crusade in the 41st Millennium, to which its homeworld contributed much war materiel by virtue of its close proximity to the theatre. The Sabbat Worlds Crusade Warmaster's constant requests for supplies and the support of the Legio Tempestus drained the world of resources and left it weak -- rendering it a perfect target for Archon Urlock Gaur, the commander of the Forces of Chaos in the Sabbat Worlds Sector. When the attack finally came, Orestes was saved only due to the support of the Legio Invicta, which was passing nearby on its way to join the forces of the Crusade on the Sabbat front.
- Epsiloid Binary Cluster Campaign (Unknown Date.M31) - A campaign conducted by the Legio Tempestus alongside Primarch Roboute Guilliman's forces during the Great Crusade against the Orks. The Legion suffered the loss of 6 Titans in the course of fighting, as well as many wounded, including the already battle-scarred Victorix Magna, the towering war machine of The Stormlord himself. Because of the injuries his war engine sustained, Princeps Senioris Cavalerio was forced to return to Mars for repairs, leaving the bulk of his Titan Legion under the command of Princeps Maximus Karania.
- Schism of Mars (Unknown Date.M31) - When the civil war broke out on Mars, the Legio Tempestus supported the Loyalist Mechanicus forces during the opening days of the Horus Heresy, defying the traitorous Fabricator General Kelbor-Hal and his Dark Mechanicum. They fought a major engagement at the Loyalist forge known as Magma City against their bitter rivals, the Traitor Legio Mortis. The Stormlord valiantly led his Legion in the destruction of the Death's Heads' lesser war machines, only to face his own destruction, along with the remainder of his war engines, at the hands of the Traitor Imperator-class Titan Aquila Ignis.
- Battle of Manachea (ca. 008.M31) - The Battle of Manachea was an early campaign conducted by the Traitor forces of Warmaster Horus against the Manachean Commonwealth, an independent dominion formed as a self-governing sub-sector within the Cyclops Cluster. Considered the lynchpin of the Coronid Deeps, it was also the principal axis of Imperial power based in the northern Imperium. The two systems of Manachea -- principally the Hive World of Manachea Vysidae, which in terms of population and industry the equal of any of the great hive worlds of the Segmentum Solar, and Port Maw which, while still under partial construction and expansion, were one of the most powerful Imperialis Armada bases in the northern Imperium. With the help of the Black Magos of the Dark Mechanicum Forge World of Cyclothrathe, the had secretly undermined the defences of the Manachean Commonwealth. In a surprise attack, the Death Guard Legion, alongside Traitoris Perdita elements of the Legio Tempestus, attacked Manachea, while the Sons of Horus launched a dual-pronged attack -- a speartip assault on Port Maw and a simultaneous assault alongside their Death Guard allies on Manachea. Within a span of eleven days of brutal fighting, Manachea and everything on it, belonged to the Warmaster.
- Battle of Beta-Garmon, "The Titandeath" (006-013.M31) - The Legio Tempestus took part in the long and savage Beta-Garmon campaign, which included hundreds of war zones across dozens of worlds. During this conflict, the Legio Tempestus was supported by the Knights of House Malinax and House Turbidos. Even before the greater armies of the Warmaster Horus reached the star cluster, the battle lines had long since been drawn, and fighting had been going on for many Terran years. It was a cauldron of battle that would consume millions of lives before its end and see the demise of entire Titan Legions, earning this campaign the dire moniker of the "Titandeath." The Beta-Garmon Cluster, also known as the gateway to the throneworld of Terra, was the last hurdle that the Warmaster Horus' forces had to overcome before they reached the Imperium's capital world. Heavily fortified by the Loyalists, Beta-Garmon would become one of the greatest and bloodiest battles of the Horus Heresy, as well as one of the longest-lasting.
- Second Aegisine Crusade (633.M39) - The Second Aeginsine Crusade was launched by the Imperium of Man to reclaim the worlds of the dread Sub-sector Mandragora in 633.M39 after it had lost contact with the Imperium for centuries under a pall of Warp Storms. The Red Scorpions Space Marine Chapter gained high honour for their role in the later phases of the Imperial Crusade which re-conquered the worlds around the former Sub-sector capital world of Hecuba. These worlds had fallen under the tyranny of a heretical sect of the Adeptus Mechanicus based on the once-proud Forge World of Shaehol. Its defences were thought to be impenetrable, and the Crusade's command elements feared that it might be impossible to retake without the use of orbital bombardment -- an alternative that might render many of the planet's assets irrecoverable. The Red Scorpions volunteered to make the initial insertion via a concerted Drop Pod attack, which was later supported by Thunderhawk gunships. In short order, the Space Marines established a beachhead against nigh-overwhelming resistance. Over the course of nearly twenty-four solar hours, the Battle-Brothers fought wave after wave of corrupted Mechanicus forces, granting the Battle Titans of the Legio Tempestus an opportunity to land and deploy their forces. Without the Space Marines' sacrifices, the Collegia Titanica forces would have suffered unacceptable losses in the course of their insertion. Over the next two standard years, the Red Scorpions Chapter fought side by side with the other members of the Crusade, eventually cleansing the world of its traitorous infestation and liberating its manufactoria so that they could once more support the Crusade's efforts. When at last the conquest was over and the Red Scorpions took their leave of the planet, the Mechanicus lords of war did them homage, as towering Imperial Knights and Titans lined the route taken by the Red Scorpions as they marched to the landing zones, bowing to them in homage as they passed by.
- Defence of Orestes (779.M41) - The homeworld of the Legio Tempestus, the Forge World of Orestes, was invaded by a large force of Traitor Titans during the Sabbat Worlds Crusade, to which the world had contributed much war materiel and for which it was a vital source of supply by virtue of its close proximity to the theatre. The Crusade Warmaster's constant requests for materiel and the support of the Legio Tempestus had drained the world of resources and left it weak -- rendering it a perfect target for Archon Urlock Gaur, the commander of the Forces of Chaos in the sector. The Dark Mechanicus in the Archenemy's service blinded the planet's sensors and allowed bulk landers to set down in the Astrobleme region and disgorge their engines of war. As a result of the Forge World's having met the Warmaster's demands, the Legio Tempestus had been left with only a token force of twenty-two Titans to defend its homeworld -- nowhere near enough to face an enemy Titan force seven times this size. The Legio Tempestus was unable to cover ground and found itself outnumbered, outgunned and outmaneuvered at nearly every turn, losing eight Titans in the first days of fighting. Orestes escaped swift and inevitable destruction only thanks to the arrival of the Legio Invicta, which was passing near the planet on its way to the Sabbat front. The bulk of the Legio Invicta landed in Orestes Principal, and after three days of preparation, it moved out into the Jeromihah Subsidiary and adjacent areas, engaging the forces of the Archenemy on Orestes for the first time. The Legion's efforts bore fruit, as its forces scored many Titan kills with few losses of their own, eventually causing the Traitors to converge on the ruins of Hive Argentum in hopes of drawing the two Imperial Titan Legions to full-scale battle -- a challenge which the Legio Invicta Princeps Maximus Pietor Gearhart, against the advice of a number of his senior Princeps, accepted, also wishing to wipe out the enemy. In the meantime, the Orestean Analyticae Department, at the behest of the Legio Invicta, had been reviewing pict scans of Traitor war engines in order to discover their original identities as Adeptus Mechanicus Titans, and by extension any weaknesses and construction flaws they might exhibit. To this end, the Orestean Magi opened sequestered archives, containing materials pertaining to the Horus Heresy and the times before the founding of the Imperium. Amongst these, a document proving beyond the shadow of a doubt that the Emperor of Mankind was not the Omnissiah was discovered, and leaked out of the Analyticae offices. Such revelation confirmed the beliefs of the Mechanicus of Orestes and many other Forge Worlds, and caused outrage amongst the Imperial populace of the Forge World. In the ensuing chaos, a triumvirate of conspirators -- Legio Tempestus Executor Fetial Enhort, Master of the Archives Tolemy, and Master of the Analyticae Egan -- moved in to seize power in the forge city. They had known about these revelations for several years, and were merely using the war as an excuse to open the archives and publish them. This news reached the Titans in the field as they were closing in on Hive Argentum, and caused a rift between the two Legions, for the Legio Invicta did not share the beliefs of their allies and continued to venerate the Emperor as the Omnissiah. Despite this theological strife, they continued their operations, and although they suffered some losses, they ultimately achieved a crushing victory, obliterating nearly the entire force positioned against them. Following the battle, the Legio Invicta Princeps Maximus Gearhart wished to move the forces of the two Legions back to the forge city to restore order, but was confronted by the Legio Tempestus. Despite being outnumbered by a four-to-one margin, the Legion of Orestes' acting commander issued Gearhart an ultimatum, telling him to stand with the Legio Tempestus or against it. Legio Tempestus war engines proceeded to acquire target locks on Legio Invicta machines. Bloodletting between the two Titan Legions was perhaps only averted by a miracle -- during the course of the war a large storm which blocked orbital scans emerged over the Western Prospection. This weather anomaly turned out to not be natural, but generated by a climate tower erected by the forces of the Archenemy in order to conceal a sizable part of its forces. This tower was discovered by a stray unit of the Imperial Guard which succeeded in destroying it. The emergence of this new threat posed by a previously hidden Traitor Titan battlegroup which outnumbered the remaining operational Imperial Titans caused the two Legions to set aside their religious differences and move to face it. By virtue of the skills of the Titan Princeps, the Loyalist Titan Legions succeeded in destroying this threat as well, and by the time the fighting finished, the danger of schism within the Mechanicus was already over -- Tolemy revealed to Enhort and their associate, Egan, that he had manipulated the data to produce the outcome he had desired. Enhort was infuriated, stating that altered data undermined their position and the validity of their theological claims, and attempted to contact Gearhart to acquiesce to his demands. Tolemy attempted to strangle the Executor, but was stopped by Egan, who killed him with a weapon brought to the meeting in secret -- and subsequently committed suicide, struck with grief over the fabrication that he had unwittingly assisted. Following this event, Enhort submitted to Gearhart. Orestes had been delivered from the rampaging Traitor Titans and, alongside the broader Imperium, from the danger of a terrible religious schism.
The Principia Glorianus Episloidae records that the Legio Tempestus accompanying the 12th Expeditionary Fleet was possessed of around 170 god-engines at the height of the victory over the Orks of the Epsiloid Binary Cluster, with at least 30 Titans lost by the end of those wars. When the Legion divided, perhaps a score of Battle Titans, along with a dozen badly damaged god-engines injured past use or repair, are believed to have returned to Mars with the Stormlord to form the core of the Legio Tempestus there -- this force being perhaps doubled in strength by the outbreak of the Horus Heresy.
Of these, almost all these were lost in the opening battles of the Schism of Mars and the destruction of Magma City, along with the bulk of the bonded Knight House Taranis that fought alongside them. Elsewhere, the demi-Legion under the Traitor Maximus Karania was able to field between 80-120 Titans of various classes over time, most of them of the Warlord, Reaver and Jackal pattern Warhound classes, with the forges of Esteban III able to produce new Warlord-class Titans for Karania's forces in limited numbers.
The Legion had once counted a number of Nightgaunt, Maines and Carnivore-class Titans amongst its god-engines during the Great Crusade, as well as at least one mighty Nemesis-class Titan, but most of these older patterns were believed destroyed on Mars. The latter god-engine is not known to have taken part in the battles of the age and may be ranked amongst those of the Order's forces still unaccounted for beyond the Imperium's ravaged borders.
The body of the Legio Tempestus on Mars was able to call upon three Skitarii Auxilia Legions, one of which comprised entirely armoured cohorts, all in the Martian pattern panoply of war and counted among the most respected of their kind, while its Expeditionary cadre relied on allied forces primarily for infantry support, enhanced on occasion by Taghmata forces from the world of Estaban III. In terms of allied Knight Households, the Martian Loyalists of the Legion could count upon the resolute allegiance of the powerful House Taranis, whereas Karania's force replaced this with a host of itinerant, masterless Free blade Knights who fought alongside them, first on the dark frontiers of the Great Crusade, and then later under the banner of the Eye of Horus.
As the Horus Heresy unfolded and the Legio Tempestus joined the massed hosts of the Traitors, still more elements were drawn to their banner. Freeblade Knights from a score of Houses and more swore service to the Tempestus, most obscuring their erstwhile colours in favour of darker heraldry. Later, an entire House of outcast Knights, fleeing the wrath of their staunchly Imperial liege, bent knee to the Traitor Stormlords. These demonstrated the extent of their allegiance by incorporating the heraldry of the Legion and submitting themselves to their new chain of command.
This process is believed to have been begun in the aftermath of the assault on Hive Ilium at Manachea, where several of the Stormlords Titans were laid low by the Loyalists of House Vyronii, revealing a vulnerability to such war machines which they strived to counter by acquiring allied Knights of their own. Such Knights, whether bearing the personal heraldry of a Free Blade or the fractured blue and argent of the Legio Tempestus, would serve in future battles as a skirmish line when the Tempestus took to war, particularly where the war zones involved encapsulated shattered cityscapes where their God-engines proved vulnerable to ambush.
- Deus Tempestus - This ancient and venerable Warlord-class Titan was the first God Machine of the Legio Tempestus to be constructed during the Age of Strife. At the time of the Schism of Mars, the Deus Tempestus had already been interred in the Ascraeus Chasmata for half a millenium, and had not moved as much as a single joint in two centuries. After Princeps Senioris Cavalerio's internment in an amniotic tank following the destruction of his Titan, the Victorix Magna, he assumed command of this august war engine as he prepared for what would be his last battle -- the defence of Magma City from the Dark Mechanicus and the Legio Mortis.
- Cullador Braxas - Warlord-class Titan and war engine of Princeps Lenix Devo during the defence of Orestes.
- Nicomach Ignix - Warlord-class Titan and war engine of Princeps Valen Lustig during the defence of Orestes. The Nicomach Ignix is noted as being the sole survivor of its battlegroup, active in the field continously for eight days, unable to return to retrofit and let its crew rest. On its way back to Mount Sigilite Assembly Yards, it was assaulted at Undergox Edge by a Chaos Warhound-class Titan supported by Dark Mechanicus Skitarii. Due to its exhaustion, the Nicomach Ignix was defeated by the smaller war engine. The Legio Invicta, which moved in to secure the area, saved it from the encroaching Skitarii and its ultimate destruction. The Nicomach Ignix was a burned-out wreck and its only surviving crewman was in a critical state. Both would take a long time to recover, and the latter was suspected to never be able to recover his sanity. Despite this, the Nicomach Ignix was used as an effective tool of propaganda by the rulers of the Forge World, who cited the war engine's steadfast valour in holding the line by itself until it was relieved at the brink of destruction by the Legio Invicta.
- Orestes Magnificat - Warlord-class Titan and war engine of Princeps Rufus Joslin during the defence of Orestes. The Orestes Magnificat was destroyed during the drive on Hive Argentum by the Traitor Imperator-class Titan Augmenautus Rex.
- Tantamount Stridex - Warlord-class Titan and war engine of Princeps Theron during the defence of Orestes. The Tantamount Stridex was noted as being one of the Legio Tempestus war machines to survive the first days of the war on Orestes largely unscathed.
- Tharsis Hastatus - Warlord-class Titan and war engine of Princeps Vlad Suzak at the time of the Schism of Mars. The Tharsis Hastatus was destroyed along with its Princeps by the Legio Mortis Imperator-class Titan Aquila Ignis during the defence of Magma City.
- Victorix Magna - Warlord-class Titan that served as the personal war machine of Princeps Senioris Indias Cavalerio at the time of the Schism of Mars. When the Legio Mortis moved to threaten the Ascraeus Chasmata at the outbreak of the Schism, Cavalerio, who was at the time on patrol with his war engines, hastened to his Legio 's fortress, greatly straining the capabilities of the Victorix Magna. Altough not a single shot was fired in the stand-off that occurred, the strain put on the machine made it susceptible to infection by the Dark Mechanicus scrapcode which was spreading over Mars. The Victorix Magna was destroyed and Cavalerio severely wounded. As a result of this, and the psychic shock of living through the death of his Titan, he received extensive cybernetic augmentation and underwent the process of complete immersion within an amniotic tank to keep his mind from shattering.
- Agrippa - Warlord-class Titan of the traitorous Legio Tempestus-faction that led the attack on Hive Ilium during the Manachean War.
- Arcadia Fortis - Reaver-class Titan and war engine of Princeps Jan Mordant at the time of the Schism of Mars. The Arcadia Fortis was destroyed along with its Princeps during the defence of Magma City.
- Metallus Cebrenia - Reaver-class Titan and war engine of Princeps Kel Sharaq at the time of the Schism of Mars. The Metallus Cebrenia was destroyed along with its Princeps during the defence of Magma City.
- Odrysian - Mars Pattern Reaver-class Titan and war engine of the Traitoris Perdita elements of the Legio Tempestus during the Great Crusade and Horus Heresy eras. This Titan served as the war engine of Princeps Nero Cotys, who was killed during the Battle of Hive Ilium during the Fall of Manachea during the opening years of the Heresy.
- Raptoria - Warhound-class Titan and war engine of Princeps Zafir Kasim at the time of the Schism of Mars. The Raptoria was destroyed along with its Princeps during the defence of Magma City.
- Raxvalian - Mars Pattern Reaver-class Titan and war engine of the Traitoris Perdita elements of the Legio Tempestus during the Great Crusade and Horus Heresy eras. This Titan led War Maniple "Telos Epsilon" during the Battle of Ilium during the Fall of Manachea.
- Astrus Lux - Warhound-class Titan and war engine of Princeps Lamnos at the time of the Schism of Mars. The Astrus Lux was destroyed along with its Princeps during the defence of Magma City.
- Durasi - Warhound-class Titan and war engine of Traitoris Perdita elements of the Legio Tempestus during the Great Crusade and Horus Heresy eras. Took part as part of War Maniple "Telos Epsilon" during the Battle of Ilium during the Fall of Manachea.
- Scorillion - Warhound-class Titan and war engine of Traitoris Perdita elements of the Legio Tempestus during the Great Crusade and Horus Heresy eras. Took part as part of War Maniple "Telos Epsilon" during the Battle of Ilium during the Fall of Manachea.
- Vulpus Rex - Warhound-class Titan and war engine of Princeps Basek at the time of the Schism of Mars. The Vulpus Rex was destroyed along with its Princeps during the defence of Magma City.
- Indias Cavalerio - Indias Cavalerio was known as "The Stormlord" and was the Princeps Senioris of the Legio Tempestus during the Great Crusade and the Schism of Mars. He commanded the Warlord-class Titan Victorix Magna, which was damaged during the Epsiloid Binary Cluster Campaign that the Legio carried out alongside Primarch Roboute Guilliman 's forces. As the result of the injury, Cavalerio was forced to accompany the detachment of the Legion's Titans headed to Mars for repairs -- this being the reason for his presence on the Red Planet at the outbreak of the Schism. Cavalerio sought to keep his Legion free from the insidious poison of the Mechanicus' politicking. He believed that the Titan Legions should remain true to their warrior ideals and not be instruments of the Magi's political will, and serve only the interests of the Imperium of Man itself. When the Legio Mortis moved to threaten the Ascraeus Chasmata at the outbreak of the Schism, Cavalerio, who was at the time on patrol with his war engines, hastened to his Legio 's fortress, greatly straining the capabilities of his Titan. Altough not a single shot was fired in the stand-off that occurred, the strain put on the machine made it susceptible to infection by the viral scrapcode which was spreading over Mars. The Victorix Magna was destroyed and Cavalerio severely wounded. As a result of this, and the psychic shock of living through the death of his Titan, he received extensive cybernetic augmentation and underwent the process of complete immersion within an amniotic tank to keep his mind from shattering. Following this, he had been deemed temporarily unfit to command the Legion, and Princeps Kel Sharaq assumed his duties as acting Princeps Senioris of the Legio Tempestus on Mars. After Cavalerio recovered enough to take to the battlefield, he took command of the first God Machine of the Legion, the Deus Tempestus, and ordered his forces to move out and aid the beleaguered Magma City, which the Legio Mortis was assaulting, supported by other Dark Mechanicus forces. He led his Legion against the impossible odds stacked against it, and succeeded in destroying all of the war engines of the Death's Heads battlegroup -- save for the towering Imperator-class Titan, Aquila Ignis, which proceeded to kill The Stormlord and obliterate the remaining Legio Tempestus war engines.
- Maximus Karania - After the division of the Legion into two commands, control of the Order's Expeditionary force was invested in the senior Princeps Maximus Karania. Where the Stormlord was known for his disdain of the political and doctrinal infighting that had befallen the Mechanicum in the later years after Unification, Maximus Karania was his mirror, subtle and secretive, although with an unimpeachable war record. So adept at intrigue was he that he had long hidden his machinations and strange preoccupations in plain sight. Unknown to most, beneath a professed orthodoxy Karania was a disciple of a certain strand of esoteric machine lore called Teleologicalica, itself a form of arcane numerology, a discipline that purported to predict imminent and all-consuming doom by reference to the patterns of past cataclysms. The Tech-Priests of Estaban III had not accepted the prevailing Mechanicum doctrine that the Emperor was one and the same with the divine being they referred to as the Omnissiah, and paid only lip-service to the Martian Doctrines. Karania's native political cunning in discovering this and his own schismatic doctrine enabled him to make private and secret alliance with the Tech-Priests of Estaban III long before the outbreak of the Horus Heresy. As time progressed, Karania moved to purge his princeps cadre according to the patterns revealed to him by the doctrines of cataclysmic teleology, ensuring that only those inducted into the discipline's innermost secrets remained within his demi-Legion, but was careful to keep such apostasy shrouded from outsiders, although it had not escaped the attention of the Warmaster's agents, who worked upon it to secure Karania to their cause. Following the death of the Stormlord at the beginning of the Schism of Mars, Karania received word from Mars that he was now the de facto master of the Tempestus loyal to the Traitors' cause, Maxim us Karania pronounced that his allied Forge World of Estaban III would henceforth and for all time enjoy the full protection of the Legion in return for the bounty of its mighty foundries. A single archival entry, recovered years after the event, suggests that even with the full extent of Karania's treachery revealed, elements of his own Legion serving further afield declined his recall order and refused to share his betrayal. These he vowed to hunt down and slay, for their very existence made a lie of the teleological precognostications by which Karania was planning and executing, his Legion's future causing him to delve ever deeper into his occult practices. In the aftermath, this hunt would lead Karania and the Traitor Tempestus along many dark and winding paths never before travelled by any Legion of the Collegia Titanicus.
- Kel Sharaq - Kel Sharaq was the Princeps of the Reaver-class Titan Metallus Cebrenia and Cavalerio's second-in-command on the Red Planet during the Schism of Mars. After Cavalerio had been deemed temporarily unfit to command the Titan Legion following his immersion in an amniotic tank, Sharaq assumed the Stormlord's duties as acting Princeps Senioris of the Legio Tempestus on Mars. He met his death in the outskirts of Magma City, when the Legio Tempestus sallied out to defend Koriel Zeth's domain from the Legio Mortis. His war engine was destroyed by the Traitor Imperator-class Titan, Aquila Ignis.
- Vlad Suzak - Vlad Suzak was the Princeps of the Warlord-class Titan Tharsis Hastatus during the Schism of Mars. He, along with his machine, had been obliterated by first salvo fired from the Traitor Imperator-class Titan, Aquila Ignis, although not before he had managed to destroy two enemy war engines.
- Jan Mordant - Jan Mordant was the Princeps of the Reaver-class Titan Arcadia Fortis during the Schism of Mars, being recently promoted from his Warhound princepture, and thus still possessing many traits characteristic to pilots of those war engines. Mordant died during the defence of Magma City, when a lucky strike damaged his Titan's neural network and the subsequent feedback agonies burned out his cerebral cortex.
- Karania - Princeps Maximus of the Legio Tempestus who had been given overall command of the bulk of the Legion's forces assigned to Roboute Guilliman's Expeditionary Fleet following the Epsiloid Binary Cluster Campaign, during which Princeps Cavalerio's Titan had been damaged, forcing the Stormlord to join the detachment of damaged war engines headed to Mars for repairs.
- Zafir Kasim - Zafir Kasim was the Princeps of the Warhound-class Titan Raptoria during the Schism of Mars. Kasim had been awarded a golden skull-and-cog medallion by the Stormlord after the Epsiloid Binary Cluster Campaign. He disliked being present on Mars and witnessing all the petty squabbles of the Mechanicum, being in these views similar to Princeps Cavalerio. Kasim died shortly after Princeps Sharaq, whom he accompanied in the defence of Magma City, when his engine was destroyed by carapace-mounted ordnance of the Legio Mortis Imperator-class Titan, Aquila Ignis.
- Lamnos - Lamnos was the Princeps of the Warhound-class Titan Astrus Lux. He was the first Legio Tempestus Princeps to die during the defence of Magma City, when a Reaver 's missile barrage stripped his Titan of its Void Shields and threw it to the ground, allowing the larger war engine to crush it beneath its bulk.
- Basek - Basek was the Princeps of the Warhound-class Titan Vulpus Rex. He died during the defence of Magma City when a scrapcode interference obscured his Titan's Auspex readings, causing his war engine to tumble into a crater, severing one its weapon arms and buckling its legs in the fall. Basek and his crew attempted to eject, but the Titan chasing them ended their lives in the mercifully swift thunder of hard rounds.
- Zem Aeschman - Zem Aeschman was the commander of the Legio Tempestus Skitarii forces on Mars during the Horus Heresy. He resolutely supported the Titans with his cybernetically augmented warriors, both in the stand-off between Legio Mortis and the Legio Tempestus near Ascraeus Mons, and in the final defence of Magma City, where he presumably died after his divisions had been wiped out.
- Sorlan Veykot - Sorlan Veykot was the Princeps Maximus of the Legio Tempestus during the Sabbat Worlds Crusade and the defence of Orestes. He died in battle against Chaos Titans whilst defending his homeworld from assault, leaving the Legion under the command of First Princeps Rufus Joslin.
- Rufus Joslin - Rufus Joslin was a First Princeps of the Legio Tempestus during the Sabbat Worlds Crusade and the defence of Orestes as well as the commander of the Warlord-class Titan Orestes Magnificat. After the death of his Princeps Maximus, he assumed his duties as acting commander of Legio Tempestus forces on Orestes. Joslin was noted for his staunch belief in the Orestean Mechanicus' theological distinction between the notions of the Emperor and the Omnissiah and was heartened by the pre-Heresy document leaked out of the Orestean Analyticae which stated that this belief was true. He understood that the Legio Invicta, which was engaged in defending Orestes from attack and was the chief Imperial force present there, would be less amused as they did not share such faith and venerated the Emperor as the Omnissiah. He was prepared to defend his forge city from Legio Invicta war engines as well if need be, and to this end had his Titans prepare target solutions on the allied Legio 's war engines prior to their mutual drive on Hive Argentum. During the fighting there, however, he met his fate as the first victim of the lumbering Traitor Imperator-class Titan Augmenautus Rex, as it drove Imperial forces out of the hive.
- Lenix Devo - Lenix Devo was the Princeps of the Warlord-class Titan Cullador Braxas and the acting commander of the Titan Legion's forces on Orestes following the death of Rufus Joslin during the battle for Hive Argentum. Like him, Devo was stoutly devoted to his forge city and was ready to defend it from the Legio Invicta, despite his forces being outnumbered four to one. After most of the fighting for Hive Argentum was finished, Legio Invicta Princeps Maximus Pietor Gearhart asked the Legio Tempestus to follow him back to the forge, and was confronted by Devo. He queried as to what Gearhart intended to do, and stated that if the Legio Invicta would move on the forge, the Legio Tempestus would stand in its way. A stand-off occurred, and bloodshed was perhaps averted only by the news of a large Traitor Titan battlegroup moving to threaten Orestes Principal Hive.
- Guido Prinzhorn - Guido Prinzhorn was the Princeps of the Legio Invicta Warlord-class Titan Dominatus Victrix during the defence of Orestes. The Legio Invicta came to the aid of the beleaguered world of Orestes following a campaign it conducted in the Beltran Cluster against the Eldar. One of the victims of those graceful xenos' Titans was the Princeps of the Dominatus Victrix. The Orestean Magi agreed to repair the war engine in their facilities, and the Legio Tempestus offered one of its Princeps -- Guido Prinzhorn -- to allow the machine to fight. As all Proximus Pattern Warlord-class Titans, the Dominatus Victrix required a full-immersion amniotic interface to operate it, and this Prinzhorn could provide. Despite being a young Princeps, and one who has never seen actual combat but only simulations, Prinzhorn was interred in an amniotic tank. He would be assisted by one of the surviving Moderati of Dominatus Victrix, Zane Tarses, as well as crewmen drawn from the Legio Invicta reserve. Prinzhorn was afraid of his first real command, and was predictably less able than an experienced war engine officer. He was aided in his charge by the veteran Moderatus, even though he was initially reluctant to accept this help. Following the battle for Hive Argentum, after the publication of revelations which allegedly proved the truth of the Orestean heresy, Legio Invicta Princeps Maximus Pietor Gearhart wished to move the forces of the two Legions back to the forge to restore order, but was confronted by the Legio Tempestus. Despite being outnumbered by a four-to-one margin, the Titan Legion of Orestes' acting commander issued Gearhart with an ultimatum, telling him to stand with the Legio Tempestus or against it. When Legio Tempestus war engines acquired target locks on Legio Invicta machines, Prinzhorn did the same, but was stopped by Tarses, who forced the Princeps to shut down the Titan at gunpoint. Bloodletting between the two Legions was only averted by the emergence of a new threat posed by a previously hidden Traitor Titan battlegroup.
- Valen Lustig - Valen Lustig was the Princeps of the famed Warlord-class Titan Nicomach Ignix. Lustig and his crew were noted for being the sole survivors of their battlegroup, active in the field continously for eight standard days with no sleep or rest. On their way back Mount Sigilite Assembly Yards, they were assaulted at Undergox Edge by a Chaos Warhound-class Titan supported by Dark Mechanicus Skitarii. Due to its exhaustion, the Nicomach Ignix was defeated by the smaller war engine. The Legio Invicta, which moved in to secure the area, saved it from the encroaching Dark Skitarii and its ultimate destruction, but they were unable to help the crew -- Princeps Lustig died from exhaustion and psychostigmatic wounds, while all but one of his crewmen had been killed by Traitor Tech-Guard that managed to board the Titan in the heat of the battle. The sole survivor, Moderatus Dolf Gentrian had his socket connectors shot off while connected to the Titan's Mind Impulse Unit. The state he was in led the medicae to believe that he might never recover his sanity. The Nicomach Ignix itself was a burned-out wreck, and both of them would take a long time to recover. Despite this, the Nicomach Ignix was used as an effective tool of propaganda by the rulers of Orestes, who cited the war engine's steadfast valour in holding the line by itself until it was relieved at the brink of defeat by the Legio Invicta -- no mention was made of the Titan crew's fates.
- Enhort - Enhort was an Executor Fetial, a diplomat, of the Legio Tempestus during the Sabbat Worlds Crusade and the defence of Orestes. He took part in a conspiracy to topple the world's ruling Adept Seniorus and bring to the light of day the revelations concerning the Emperor's non-divinity, the existence of which he had already been aware of for several standard years. Although his co-conspirator, Master of the Archives Tolemy, was said to be operating only for the sake of personal aggrandisement and cared little for matters of faith, Enhort was a staunch idealist on this subject, believing that it was his duty to disseminate the truth. Legio Invicta Princeps Maximus Pietor Gearhart, who had learned of the details of the coup, ordered Enhort to step down after the latter had assumed the position of Adept Seniorus. Enhort, believing he was in the right, was not about to accede, and instead issued a counter-demand. Violence between the Legio Invicta and the Orestean forge city, and the Legio Tempestus which would invariably defend it, was averted only by the emergence of a new threat posed by a previously hidden Traitor Titan battlegroup. The two Imperial Titan Legions sallied forth to engage them, and before the fighting finished, the danger of schism within the Mechanicus was already over -- Tolemy revealed to Enhort and their associate, Egan, that he had manipulated the data to provide support for the Orestean heresy's theological claims. Enhort was infuriated, stating that altered data undermined their position and the validity of their theological claims, and attempted to contact Gearhart to aquiesce to his demands. Tolemy attempted to strangle Enhort, but was stopped by Egan, who killed him with a weapon brought to the meeting in secret -- and subsequently committed suicide, struck with grief over the falsehood he had assisted. Following this event, Enhort submitted to Gearhart. His ultimate fate is unknown.
The Legio Tempestus' Legion colours are cobalt blue and silver.
The Legio Tempestus' Legion badge is a large eagle, wings elevated, centered on a white circle, outlined in black, centered on a field of cobalt blue. Lightning bolts, reminiscent of the Unification War-era lightning heraldry of the Emperor himself, are prominently displayed, radiating frffom beneath and above the eagle. This more than likely alludes to the Legion's epithet, the "Stormlords." Traitoris Perdita elements of the Legio Tempestus would often display the Eye of Horus, somewhere on their Honour Banners, to denote their loyalty to the Warmaster during the Horus Heresy.
The novel Mechanicum indicates that the Legio Tempestus uses the name Princeps Maximus for a Senior Princeps, and Princeps Senioris for a Grand Master. However, the novel Titanicus indicates instead that the Legion uses the names First Princeps and Princeps Maximus for the Senior Princeps and Grand Master respectively -- exactly like the Legio Invicta. It is possible that the Legio changed its nomenclature in the ten millenia between the events depicted in these two novels, although it is also plausible that the author used the nomenclature of the Legio Invicta for clarity's sake -- especially so as the Legion 's officers are never addressed by rank in a conversation.
- Adeptus Titanicus - The Horus Heresy: Titandeath (Specialty Game), pg. 95
- Deathwatch: Honour the Chapter (RPG), pg. 35
- Imperial Armour Volume One - Imperial Guard and Imperial Navy, pg. 8
- The Horus Heresy - Book Four: Conquest (Forge World Series) by Alan Bligh, pp. 49, 138-143
- Warhammer 40,000: Rulebook (6th Edition), "Force Dispositions in the Third War for Armageddon," pg. 193
- Mechanicum (Novel) by Graham McNeill
- Titanicus (Novel) by Dan Abnett