Age of the Imperium

The Age of the Imperium is the name given by Imperial lexographers and historians to the period of human history that represents the present time in the Warhammer 40,000 universe. The Age of the Imperium began in the 31st Millennium when the Emperor of Mankind emerged from long centuries of obscurity to unify Terra beneath his rule and end the terrible suffering and civil conflicts of the Age of Strife. The Emperor forged a political and military alliance with the Cult Mechanicus that had reunified the Forge World of Mars beneath its rule and together the two most populous worlds of humanity forged the Imperium of Man. Using the advanced technology of the Mechanicus, the Emperor created the twenty Space Marine Legions of the First Founding to launch the Great Crusade, an attempt to reunify all the human-settled colony worlds across the Milky Way Galaxy under a single government once more.

The Rise of the Emperor (c. M30 - M31)
During the Age of Strife the great Warp Storms that heralded the birth of the Chaos God Slaanesh following the Fall of the Eldar had separated Terra from its interstellar colonies and plunged all the human civilizations across the Milky Way Galaxy into disarray and chaos. When the storms abated with the emergence of Slaanesh in the Warp, a new leader for humanity known only as the Emperor of Mankind emerged on Terra, the ancient homeworld of Mankind. He conquered the raging warlords of late Age of Strife Terra in a series of great campaigns that made use of genetically engineered warriors later called the Unification Wars and entered a military and political alliance with the Cult Mechanicus on Mars. that gave formal rise to the Imperium of Man following the signing of the Treaty of Mars in the late 30th Millennium. With his twenty Legions of genetically engineered Space Marines created from the the genetic material of the lost Primarchs, the Emperor planned to reunite all of Mankind beneath his benevolent rule, banishing the violence, superstition and injustice that had ruled humanity throughout the five millennia of the Age of Strife.

The Great Crusade (c. M31)
The Great Crusade lasted for 200 standard years in the early 31st Millennium and brought many long lost star systems into the fold of the newborn Imperium of Man. Under the War Council of the Emperor and his rediscovered Primarchs, vast Expedition Fleets comprised of the Imperial Army and the twenty Space Marine Legions fought back aliens, feral human tribes, petty human dictators and the Warp-tainted forces that had gained control of large portions of human-settled space during the Age of Strife. Once a human-settled world had been pacified, it was brought into "Imperial Compliance" by a new Imperial Planetary Governor chosen by the Emperor and it was often occupied by a unit of the Imperial Army that was left behind to complete the integration of the planet into the Imperium while the Expedition Fleet moved on to its next target.

The Horus Heresy (c. M31)
The Great Crusade ended with the nightmarish Imperial civil war known as the Horus Heresy. The Warmaster Horus, the greatest among the Primarchs, leader of the Luna Wolves Space Marine Legion and the most favoured son of the Emperor, fell under the influence of the Ruinous Powers of Chaos. In an attempt to usurp his creator and take his place as the Master of Mankind, Horus took control of a third of the entire Imperium's armed forces (including a full half of the Space Marine Legions and much of the Imperial Army and the Adeptus Mechanicus) and marched towards Terra where his forces laid siege to the Imperial Palace. He was ultimately slain aboard his own flagship, the battle barge Vengeful Spirit, during a daring assault by Loyalist Astartes forces led by the Emperor, but the Emperor was mortally wounded in the final battle and was forced into a state of semi-consciousness interred within the ancient cybernetic life support system and psychic amplifier known as the Golden Throne. The Imperium was left rudderless and at the very brink of collapse following the Heresy.

The Age of Rebirth (c. M31 - c. M32)
During the Age of Rebirth the Imperium of Man slowly recovered from the Horus Heresy.The myriad wars of the Great Scouring were fought in the years immediately after the end of the Horus Heresy and the death of the Warmaster. In a lengthy campaign, the Imperium's forces hunted and banished the remaining Traitor Legions from the occupation of human space. Eventually the Chaos Space Marines and the Ruinous Powers' other followers among the Forces of Chaos found refuge in the massive Warp rift known as the Eye of Terror. For a time the Imperium knew peace from the corrupted followers of the Chaos Gods. At the same time, many alien races that had been fought during the Great Crusade reappeared in human space to take advantage of the disruptions caused by the Horus Heresy and plagued the vulnerable worlds of Man. In order to prevent a single person from controlling as much military power as Horus had mastered and eliminate the risk of another large-scale civil war, numerous reforms were enacted to reshape the Imperium's political and military structure. The Imperial Army was divided into the land-based forces of the Imperial Guard, and the space-based forces of the Imperial Navy, each with a separate chain-of-command structure and bureaucracy. The remaining nine Loyalist Space Marine Legions adopted the Codex Astartes written by the Ultramarines' Primarch Roboute Guilliman and were split into the many smaller Space Marine Chapters of the Second Founding that were comprised of only 1,000 men each along with their own supporting spacecraft and planetary fiefdoms.

The byzantine politics of the Imperium took a calamitous turn in 546.M32 when the High Lords of Terra, the successors of the Council of Terra that had been established to administer the day-to-days affairs of the Imperium and now ruled in the Emperor's name were slain to a man on the orders of Drakan Vangorich, the Grand Master of the Officio Assassinorum. A Space Marine retribution force drawn from the Halo Brethren, Imperial Fists and Sable Swords Chapters tracked the Grand Master to an Assassinourm temple. The commander of the Astartes strike force was assassinated as soon as he made planetfall, but the remaining Battle-Brothers carried out the attack without him. Inside the temple they were attacked by 100 Eversor Assassins. Only a single Space Marine survived to reach the Grand Master and end his life with a boltgun. The Imperium descended into anarchy for several years as new High Lords rose to power.

The Forging (c. M32 - c. M35)
The Forging is also sometimes known to Imperial historians as the Golden Age of the Imperium. During this period the Adeptus Terra brought the most important human-settled star systems of the galaxy that had not been reached by the Great Crusade under Imperial control and expanded the interstellar borders of the Imperium. Internal stability was gained with the establishment of Astropath Choirs on countless worlds, which allowed a reliable network of interstellar superluminal communication to function using the power of an Astropath's telepathy to send and receive mesages across light years. This period also saw the slowing of the decline in the Imperium's technology and the growth of the interstellar economy due to the rediscovery of a valuable Standard Template Construct (STC) database from the Dark Age of Technology in the Cana System as the Imperium expanded. Once more the Imperium repelled the forces of Chaos renegades, heretics and aliens alike across the galaxy and reclaimed countless lost and rebellious regions for the human race.

In 265.M33 Admiral Usurs of the Imperial Navy was cast down by the High Lords of Terra for becoming too ambitious. However, he is still too powerful within the Navy to be executed without intiating a costly civil war, so he is instead dispatched on an Explorator mission to the intergalactic gulf beyond the Milky Way. For the following decade, Usurs' reports reach Terra by Astropath, detailing the conquest of new star systems for the Emperor. After two decades, these reports finally cease. Contact is never reestablished with the star systems Usurs mentioned in his reports.

In 401.M34 the terrible event known as the Howling unfolded. Black Templar Space Marines ended the Catelexis Heresy by executing the Cacodominus, an alien cybernetic psyker whose formidable powers allowed it to psychically control the populace of thirteen hundred star systems! Unfortunately, the Cacodominus' death scream was amplified by the Warp and burned out the minds of a billion human Astropaths as well as distorting the beacon of the Astronomicon. Millions of starships were lost in the resulting upheaval and entire sub-sectors of the Imperium slid into barbarism without the dictats of the Administratum to guide them.

The Nova Terra Interregnum (c. M35)
The Nova Terra Interregnum is also known as the Time of the Twin Empires and it lasted for 900 standard years during the 35th Millennium. During this period the rebellious Ur-Council of Nova Terra dismissed the authority of the High Lords of Terra and claimed separate rule over the Imperium's Segmentum Pacificus. After almost a millennium of low-grade civil war and political maneuvering, the Cataclysm of Souls in 975.M35 reunited the Imperium. In that year the Ecclesiarchy tried to transform the Imperium into a theocracy and usurp the power of the rest of the High Lords of Terra. Their efforts ended only in stirring up massive religious civil wars against the Ur-Council who were denounced as heretics who stood in defiance of the will of the God-Emperor when they rejected the Ecclesiarchy's attempts to increase its power over the state. This religious rebellion on many worlds of the Segmentum Pacificus ultimately overthrew the Ur-Council and restored the rule of the High Lords over the entirety of the Imperium's territory, though the power of the Ecclesiarchy had been increased throughout the Imperium as a result.

The Age of Apostasy (M36)
The Age of Apostasy is another era of Imperial civil war and is considered to be one of the bloodiest eras of the Imperium's history after the Horus Heresy. The Age of Apostasy is marked by the Reign of Blood, when the insane tyrant, High Lord Goge Vandire, became both Ecclesiarch of the Adeptus Ministorum and High Lord of the Adeptus Administratum through bribery, blackmail, coercion and murder. Vandire started an period of time known as the Reign of Blood where multiple wars of faith were fought as Vandire attempted to gain control of the Imperium. The Reign of Blood lasted for 70 years before a messenger delivered the news that heralded its end. On the world of Dimmamar, a man named Sebastian Thor and his sect, the Confederation of Light, denounced High Lord Vandire as a traitor to the Emperor. As an accomplished orator, Thor was able to sway billions to his cause. Eventually Vandire was besieged on Terra by several Space Marine Chapters and several Imperial Guard Regiments. The Space Marines' fleet unleashed a massive orbital bombardment which caught most of the traitors in the open. Lord Vandire was killed by his bodyguards, the Brides of the Emperor, who were convinced that they had been tricked into betraying the Emperor by Vandire. In the aftermath, the Ecclesiarchy was reformed, and the Brides of the Emperor were reformed into the Adeptus Sororitas, the Sisters of Battle, the armed forces of the Ecclesiarchy and the Chamber Militant of the Inquisition's new Ordo Hereticus. The Ordo Hereticus was intended to root out the internal enemies of the Imperium and prevent the emergence of another Goge Vandire who sought to serve his own selfish ends rather than the will of the Emperor.

The event known as the Plague of Unbelief is also considered part of the Age of Apostasy of the 36th Millennium, although it occurred several decades after High Lord Goge Vandire's death and Sebastian Thor's ascension to the position of Ecclesiarch. Many false prophets appeared throughout the anarchic Age of Apostasy, some little more than madmen leading rebel armies, others spiritual demagogues who commanded worlds and armies. The most powerful of these was the Apostate Cardinal of Gathalamor, Bucharis, whose heresies reached such proportions they became known as the Plague of Unbelief, not to be confused with the Curse of Unbelief, a potent arcane disease spread by servants of the Chaos God Nurgle in the 41st Millennium and better known as the Zombie Plague.

The Age of Redemption (c. M37)
The Age of Redemption marked the era when the Imperium recovered from the sins of apostasy in a rain of blood and tears. The Imperial Cult grew in zeal as never before. Heretic pyres burned night and day on a thousand Imperial worlds as the people of the Imperium sought to mortify their sins against the God-Emperor through the scourging of the flesh of others. Crusade after crusade was launched by the Space Marines and other Imperial military forces to recapture the lost wealth of the Imperium and push back the hordes of Chaos, Orks and other alien threats to humanity. This religious fervour eventually peaked in an orgy of fanatical devotion to crusading in the Emperor's name and thousands of worlds were left with inadequate defenses as sector fleets of the Imperial Navy, Space Marine Chapters and Imperial Guard Regiments are drawn into longer and more terrible Redemption Crusades spurred on by this religious fanaticism.

Among the most devastating of these conflicts were the Abyssal Crusade and the Occlusiad. The Abyssal Crusade of 321.M37 began when Saint Basilius found thirty Space Marine Chapters wanting in their devotion to the Emperor. The guilty embarked upon a crusade into the Eye of Terror to earn their salvation and purge those human-settled worlds stolen from Mankind by the birth of the Dark Prince of Pleasure, Slaanesh. The Occlusiad of 555.M37 started when the northwestern fringe of the galaxy was ravaged by the heretics known as the Apostles of the Blind King, rogueTech-priests who viewed humanity as an utter affront to the Machine God. The Apostles had uncovered wondrous artefacts from the Dark Age of Technology that made possible the transformation of ordinary stars into supernovae. The constellations of the galaxy were changed forever when the Apostles purged the outer Segmentum Obscurus of human life using these weapons. War raged for a decade until the Navigator Joyre Macran discovered the palace-warship of the Blind King hidden in a fold of the Warp. Escaping with this crucial intelligence, Macran guided the Imperial Navy's Emperor-class battleship Dominus Astra to the palace's location. The Blind King was killed and the genocide ended when the Dominus Astra's lance batteries pierced the palace-warship's hull and without his leadership the Apostles were swiftly overcome and their weapons hidden away in the vaults of Mars.

The Waning (c. M38 - c. 750.M41)
With the Imperium's military forces in every branch utterly exhausted by the Redemption Crusades, star system after star system fell to Ork invasion, Chaos insurgence or sheer rebellion. Anarchy throughout many sectors of the Imperium was rife during a dark period in Imperial history that is now called the Waning. Ever more star systems are turned over by the Administratum to direct rule by Space Marine Chapters to preserve stability as only the Astartes possess the inviolable military strength required to restore Imperial control in the more lawless regions of the galaxy.

This period saw the Macharian Conquests (also called the Macharian Crusade) of 392-399.M41 during which Lord Commander Solar Macharius, the Lord of the Segmentum Solar, mustered the greatest human army the galaxy had seen since the Great Crusade. In only five standard years, Macharius reconquered a thousand worlds on the western reaches of the Imperium and his glory carried him into the darkest sectors, places where the Emperor's light had never been known. Upon his death, the whole Imperium wept for the lost commander, but Macharius' conquered territories soon collapse into rivalry and civil war. The Macharian Heresy, as this time is now known, lasts for seventy years and is only ended through the combined efforts of one hundred Space Marine Chapters.

A Black Crusade is the term used to describe a number of mass incursions by Chaos Space Marines and the other Forces of Chaos into Imperial space from the Eye of Terror. The most prominent of these are the Black Crusades led by the Black Legion's Warmaster and Horus' successor as the greatest Champion of Chaos Undivided, Abaddon the Despoiler. The 12th Black Crusade, or Gothic War, was a vast campaign launched by Abaddon that engulfed the Gothic Sector of the Segmentum Obscurus after that sector was cut off from Imperial reinforcements and communications by a series of massive Warp Storms produced by the will of the Ruinous Powers. It consisted of hundreds of planetary invasions and naval battles spanning the time period 139.M41 - 160.M41 and only ended when Abaddon and his Chaos Space Marines were forced to retreat into the Immaterium with the arrival of Imperial reinforcements as the Warp Storms that had provided cover for their invasion finally dissipated just as mysteriously as they had begun. It saw the destruction of several planets and four of the six irreplaceable ancient alien artefacts known as the Blackstone Fortresses as well as the deaths of millions, if not billions, of Imperial citizens. Most significantly, the events of the Gothic War revealed the true nature and purpose of the ancient spaceborne alien artefacts known to the Imperium as the Blackstone Fortresses, which had been created by the Old Ones to be used against the Necrons and were capable of destabilising stars and destroying entire solar systems. Most importantly, Abaddon and the Forces of Chaos were able to escape back into the Eye of Terror with one of the Blackstone Fortresses, which was then possessed by a splinter of the mind of the Chaos God Slaanesh.

The Time of Ending (c. 750.M41 - Present)
As the threats to the Imperium grow, Mankind stands on the precipice of utter extinction. The Time of Ending is the era of humanity's judgment, where faith shall be tested by fire and all men's courage will be pushed to its limits -- and well beyond. Secession, rebellion, Chaos corruption and heresy are now rife within every corner of the Imperium. Sensing weakness, alien empires ancient and new to humanity's experience -- Orks, Eldar, Tau, Necrons and perhaps worst of all, the Tyranids -- close in from every side. The Space Marines and Imperial Guard are at war as never before, even during the Horus Heresy, defending humanity from threats within, without and beyond the boundaries of reality. This is surely humanity's darkest hour.

The Time of Ending is so named in 744.M41 when Taggarath, the Seer of Corrinto, proclaims the approach of the End Times. He prophesies a time of unprecedented upheaval, in which even the light of the Emperor is swallowed in darkness. Taggarath is swiftly executed by the Inquisition for heresy -- and to keep his prophecies unknown by the wider Imperial public.

In 745.M41 the Tyranids first enter the galaxy and the Tyrannic Wars begin. Hive Fleet Behemoth destroys the Imperial star systems of Tyran (for which the Tyranids are named) and Thandros. Later that same year, Hive Fleet Behemoth descends upon the Realm of Ultramar, the fief of the Ultramarines, laying waste to several worlds and badly damaging the Space Marines' greatest Chapter. The threat of Hive Fleet Behemoth is ended under the guns of two entire Imperial Navy battlefleets. Imperial Commanders across the Ultima Segmentum look to their borders with growing unease.

757.M41 sees the first recorded incidence of the dread Zombie Plague on the world of Hydra Minoris. A quarantine is imposed by the Imperial Navy, trapping 23 billion uninfected people alongside a rising tide of the hungry and mindless undead of Nurgle.

In 963.M41 the Imperium made first contact with the Tau Empire when the Ultramarines clashed with a Tau expeditionary fleet for control of the cursed planet of Malbede. When the conflict awakened the Necrons whose tombs were hidden on Malbede, the Ultramarines joined the Tau in a temporary alliance to defeat the emerging Necrons. In the wake of the battle, Exterminatus is proclaimed on Malbede by the Ultramarine Chapter Master Marneus Calgar, but he generously allows the Tau to evacuate before the surface of the planet is destroyed. Unfortunately, the Imperium of Man now finds itself facing two more alien enemies -- the humanoid Tau who seek to expand their growing interstellar empire to "serve the Greater Good" and the unholy Necrons who seek to wipe the galaxy clean of all sentient life once more as sacrifices to their vile Star Gods, the C'tan.

In 993.M41 the Ultramarines crush a rebellion on the industrial world of Ichar IV, only to find themselves in the forefront of a desperate defence against the arrival of the Tyranids' Hive Fleet Kraken. Elsewhere, the Eldar Craftworld Iyanden is ravaged by other tendrils of the Kraken. Two Space Marine Chapters--the Scythes of the Emperor and the Lamenters--are all but wiped out by the Hive Fleet and hundreds of Imperial worlds are lost to the ravenous Tyranids before the incursion is finally halted.

In 997.M41 humanity peers into the abyss when the twin tendrils of Hive Fleet Leviathan emerge from intergalactic space and strike at the underbelly of the Imperium from below the galactic plane, cutting a swathe of truly horrific destruction through Segmentum Tempestus, Ultima and Solar. It becomes clear that the two previous Tyranid incursions into the galaxy were only reconaissance expeditions for the main Hive Fleet.

In 999.M41 Abaddon the Despoiler launches the 13th Black Crusade out of the Eye of Terror with the intent to seize the world of Cadia and the Cadian Gate it defends and so allow the Forces of Chaos to assault the heart of the Imperium for the first time since the Horus Heresy. The Imperium is forced to mobilise the largest military force in its history since the Heresy to meet the massive Chaos assault. The valour of the Imperial defenders is ultimately rewarded. Though the Forces of Chaos manage to secure a foothold on the surface of Cadia, the Imperial Navy defeats the Chaos warfleets in orbit of the fortress world and traps the Chaos armies on the world below. As long as the Imperium can maintain its orbital superiority, a stalemate will be maintained. However, defending that stalemate grows more difficult with every passing month as the Tyranids of Hive Fleet Leviathan march ever closer to Terra, drawn by the light and power of the Astronomicon in the Warp inevitably towards the heart of the Imperium. The heroism of the Space Marines and the Inquisition manages to slow down the progression of the massive Hive Fleet, but its ultimate objective is never in doubt.

Finally, even as multiple calamities loom over the Imperium, the Adeptus Mechanicus has learned a terrifying secret: the mechanisms of the Golden Throne have begun to fail and they no longer possess the knowledge required to repair that ancient piece of technology. Unless something can be done, the God-Emperor will die and then humanity will face the drawing darkness alone...