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. While this campaign proved largely successful in reunifying the majority of the human race, that unity was eventually destroyed by the terrible galaxy-wide civil war known as the Horus Heresy. Half of the Imperial armed forces, led by the Emperor's favoured son, the Warmaster Horus, were corrupted by the Dark Gods of Chaos. The Traitor Legions and their allies launched themselves in an assault upon the Imperium that ultimately led to Horus' death, the Emperor's eternal internment within the Golden Throne and the dawn of a new age of stagnation and constant warfare.
The Rise of the Emperor (c. M28 - M30)
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 civilisations 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. To carry out the Unification of Terra the Emperor creates the first of his genetically-enhanced warriors who are known as Thunder Warriors and later the nascent Legiones Astartes, the precursors to the present-day Adeptus Astartes. Wrought to be living weapons, the Thunder Warriors were known to be physically stronger, more savage and more potent in combat than the later Astartes, though they were not as long-lived. With his legions of Thunder Warriors, the Emperor cast down the remaining tyrants of Ancient Earth -- bloody-handed warlords of the late Age of Strife-era Terra in a series of great campaigns later called the Unification Wars. Alongside this ascendency would come a rebirth of civilisation and government with the Emperor founding an all-embracing civil administration to order and rebuilt His world, and concentrate such learning and knowledge that could be salvaged from the dust of ages in houses of learning and education. The unification of Terra would only be the start.
The Emperor then sought a negotiated alliance with the Mechanicum Parliament on the red planet of Mars. The Emperor entered a military and political alliance with the Lords of the Red Planet, known as the Treaty of Mars, which was also known as the Treaty of Olympus Mons to the Mechanicum, the formal name given to the binding agreements that regulate the coexistence of the Imperium of Man and the Cult Mechanicus. This gave formal rise to the nascent Imperium of Man in the late 30th Millennium. The Treaty of Mars granted political autonomony to the Mechanicum of Mars and its Forge Worlds scattered across the galaxy as well as an exception to the Imperial Truth so that the Cult Mechanicus' adherents could continue to practice their faith. The Imperium would provide Navigators and Astropaths to the Mechanicum so that it could unite its far-flung empire of lost Forge Worlds and continue its sacred Quest for Knowledge across the galaxy. In exchange, the Mechanicum would supply the Imperium of Man with the weapons, starships, materiel and technicians required to initiate the Emperor's Great Crusade to reunite all of the human-settled galaxy beneath the banner of the Imperium. To symbolise the alliance created between Terra and Mars that marked the true birth of the new Imperium, the Emperor changed his personal sigil from one of a lightning bolt to the Aquila, a two-headed eagle whose heads represented the twin foundations of the new human interstellar government -- Terra and Mars, Imperium and Mechanicum.
During Old Earth's isolation in the Age of Strife, the Emperor had for long years furthered his plans and worked to make the future Imperium possible. In preparation for the re-conquest of the galaxy He conceived of and created the twenty Primarchs to be his agents of change and lords of war, long before the understanding of any save the Emperor Himself, were to be his generals and the executors of his will -- great leaders who would conquer millions of worlds in his name. Each of these genetically-engineered superhumans would have powers and skulls beyond those of any other human -- abilities possibly rivalling those of the Emperor Himself. Furthermore, no two would be alike; each would embody a different facet of war and generalship and make it his own. Together, united with the Emperor and with the Legions at his command, they would make for a force unseen and unequalled in all creation. But the Emperor's ambitions for the Primarchs appeared to be thwarted by a cataclysmic event, the true nature and scope of which has never been revealed. The Primarchs were somehow snatched away whilst still in their gestation capsules from the Emperor's gene-laboratories deep beneath the Himalazian (Himalayan) Mountains and cast in scattered disarray across the galaxy. But all was not lost.
The Emperor had managed to keep a small sample of each Primarch's genetic material and use it to create gene-seed which was implanted into the first Terran volunteers, which genetically-enhanced these elite soldiers into the first true Space Marines. It is from these soldiers that the Emperor forged the original 20 First Founding Space Marine Legions. With his Legiones Astartes, the Emperor planned to unleash a Great Crusade intended to reunite all of Mankind across the galaxy beneath his benevolent rule, banishing the violence, superstition and injustice that had ruled humanity throughout the five millennia of the Age of Strife.
Birth of the Astronomican (c. M30)
Following the successful conclusion of the Unification Wars, the Emperor first ordered the construction of the great psychic beacon, known as the Astronomican on Terra, which would enable his forces to expand the Great Crusade to the stars beyond the Sol System. Huge numbers of Tech-priests were brought from Mars to oversee the project and the majority of the Terran population were drafted to construct the towering machine-buildings needed to support this labour. At the time the Astronomican was the single largest artifice on Terra, and the entire device was merely a focus through which the Emperor could direct His fathomless psychic energies to generate a partly self-sustaining telepathic signal through the Empyrean (although few were aware of this fact). The psychic navigational beam the Astronomican generated was able to propagate through the Warp and those attuned to its unique frequencies and modulations, the Navigators, were able to use it as a beacon and pole star when plotting journeys through the Immaterium. By this beacon the Warp could be travelled at speeds and with a margin of safety that had been unprecedented, although the risk of course could never be fully mitigated. The Astronomican was an incalculable boon to both the Great Crusade and the fledgling interstellar domain of Mankind that it was creating. In a similar way, the Emperor was able to shut down the Astronomican or interrupt the beam at will. Only a handful of individuals knew that the great signal was actually powered by the Emperor's psychic powers, and they lived in fear that should He be disabled or killed, the galaxy would be plunged into a new Age of Strife. Such was the Astronomican's effect that even in that distant age of the Imperium's first founding some referred to it as the Divine Light, or the Emperor's Light, often without fully realising the literal truth of those words. The sacred duty of powering the massive psychic beacon would eventually be shifted to a great choir of 10,000 Sanctioned Imperial psykers after the Emperor was interred within the Golden Throne, heralding the birth of the Imperial Adepta that would become the Adeptus Astronomica.
The Great Crusade (c. 798.M30 - c. 005.M31)
The Emperor emerged from the anarchy of sundered Terra and lead the massive interstellar campaign to reunite Mankind. The Great Crusade was spearheaded by the newly formed Space Marine Legions, who were armed by the recently allied factories of Mars. Battles unnumbered were fought and the Expeditionary Fleets of the Space Marines, supported by the regiments and starships of the newborn Imperial Army, prove unstoppable. Aliens and Warp creatures are driven back, planets are reclaimed and the missing Primarchs are discovered to have been scattered through the Warp to human-settled worlds across the galaxy. The Emperor preaches three great truths in his reconquest of the galaxy: genetic corruption must be sought out and eradicated; psykers are to be rooted out, kept under control, and handed over to Imperial agents for evaluation; and destructive aliens are to be rendered powerless. The Great Crusade lasted for 200 standard years, into the early years of the 31st Millennium, and brought many long lost star systems into the fold of the newborn Imperium of Man. Under the command of the War Council of the Emperor and his rediscovered Primarchs, vast Expeditionary 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. Part of this process included the rooting out of any superstitious or religious beliefs of the population with a respect solely for reason and the measured advancement of science and technology, an atheistic belief system known as the Imperial Truth. It was often occupied by a unit or units of the Imperial Army that were left behind to complete the integration of the planet into the Imperium while the Expeditionary Fleet, led by Astartes, moved on to its next target. As the Primarchs took control of the Space Marine Legions that had been crafted from their gene-seed, the Great Crusade separated, moving in many directions and reaching far across the galaxy. The Emperor eventually returned to Terra following the Ullanor Crusade against the Orks, leaving the Warmaster Horus, foremost amongst the Primarchs and the most beloved son of the Emperor, to finish off the great drives of human expansion. It is these deeds and countless battles that truly create the Imperium of Man in the minds and hearts of humanity across the galaxy.
The Horus Heresy (c. 005-014.M31)
The Great Crusade ended with the nightmarish Imperial civil war known as the Horus Heresy. The Warmaster Horus, the greatest among the Primarchs and the leader of the Luna Wolves Space Marine Legion as well as 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 half of the Space Marine Legions, four Titan Legions and an untold number of formations from the Imperial Army and the Adeptus Mechanicus) and marched towards Terra where his forces laid siege to the Imperial Palace. It proved to be a bitter and destructive civil war that lasted for seven standard years; across space and upon many planets, brother fought brother. Immortalised by many later Imperial legends, the Battle of Terra and the Siege of the Imperial Palace mark the epic climax of the Heresy, with countless heroic actions and notorious deeds to mark the end of the founding era of the Imperium. Horus 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 by his mortal injuries and interred within the ancient cybernetic life-support system and psychic amplifier known as the Golden Throne. The Imperium was left leaderless and at the very brink of collapse following the Heresy.
The Great Scouring (c. 014-021.M31)
The Great Scouring, or simply The Scouring, was the Imperium of Man's great counter-offensive against the Traitor Legions. It began immediately after the end of the Horus Heresy following the death of the Warmaster Horus and the failure of his Siege of the Imperial Palace during the Battle of Terra in the early 31st Millennium. It succeeded in driving the Forces of Chaos from Imperial space into finding a refuge in the permanent Warp Storm known as the Eye of Terror. Before actually being confined for all time within the life support mechanisms of the Golden Throne, the Emperor had pronounced judgment on the Traitors: he declared them Excommunicate Traitoris, and determined that they were to be driven into the hellish region of the Warp rift called the Eye of Terror, which would hold them for all eternity. All records and memory of the Traitor Legions were to be expunged from the Imperial archives. Worlds such as Istvaan V and Davin would be scoured clean of all life because of their corruption by Chaos. The Traitor Legions' associated troops from the Dark Mechanicus, the Titan Legions or the regiments and starships of the Imperial Army and Imperial Navy that had turned to Chaos were to be destroyed or driven into the Eye. It would be as if the Traitor Legions had never existed to sully the Imperium with their betrayal. After the death of Horus, those Traitors who had not been slain outright during the Siege of the Imperial Palace fled before the vengeful wrath of the Loyalist forces. Many made good their escape into unexplored space or disappeared into the Eye of Terror or other, lesser-known Warp rifts such as the Maelstrom. Fighting continued for another seven standard years after the Heresy had ended with Horus' death on the bridge of his great flagship, the Vengeful Spirit, before the Traitor forces were wholly destroyed or exiled into the Eye of Terror. Many Chaos-corrupted star systems were cleansed and placed under the watch of the newborn Inquisition. The Emperor's dream of a new age of enlightenment, a time when Mankind was freed from superstition and ignorance, would turn into something far different. The Great Scouring would be followed by the ten millennia long era known as the Age of the Imperium.
The Second Founding (c. 021.M31)
In the midst of the Great Scouring campaign, the Second Founding occurred. The remaining 9 Loyalist Space Marine Legions were disbanded to form the far smaller 1,000-man organisations known as Chapters, in accordance with the established dictates of Primarch Roboute Guilliman's Codex Astartes. A portion of the Space Marines, now collectively known as the Adeptus Astartes, maintained their parent Legions' original names, badges and colours whilst the remaining Chapters took on new names and heraldry. The majority of these Second Founding Chapters still serve the Imperium today.
The Time of Rebirth (c. M31 - c. M32)
During the Time 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 traitorous 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 at the hands of Roboute Guilliman to reshape the Imperium's political and military structure. In this way the men and women of the Imperium could face the new post-Heresy realties of an interstellar government where the Emperor was no longer capable of carrying on the day-to-day tasks of interstellar governance. 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 Orks rampaged across the Imperium on a massive scale in 544.M32. The number of Greenskin attacks grew until it became the greatest Ork invasion that the galaxy had ever know, eclipsing even the Ork WAAAGH! defeated by the Emperor and Horus during the UIlanor Crusade, which had earned Horus the title of Warmaster. Nothing was safe from the Orks' primal desire to conquer the galaxy and their widespread advances were only halted when the Imperium resorted to the use of the most extreme measures, at great cost to the Chapters of the Adeptus Astartes.
The byzantine politics of the Imperium took a calamitous turn in 546.M32 in an event remembered as The Beheading 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 Grand Master Vangorich and end his life with a Bolter. 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, with major hubs established on the best-garrisoned Imperial worlds, including Armageddon, Bakka and Macragge. This allowed a reliable network of interstellar superluminal communication to function using the power of an Astropath's telepathy to send and receive messages 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.
The Emperor, always an object of veneration, only increased his devoted following of worshippers after being joined to the Golden Throne. Many Imperial cults dedicated to the worship of the Emperor as the God of Mankind arise over the following centuries, the majority of which were united into a centralised religious body known as the Ecclesiarchy. This powerful church gains momentum until, in the 32nd Millennium, it is finally granted the status of the official state religion of the Imperium and the title of Adeptus Ministorum. It is only a few centuries later that Ecclesiarch Veneris II receives a seat amongst the High Lords of Terra, and after 300 standard years, the seat reserved for the Ecclesiarch is made permanent within the ranks of the Senatorum Imperialis.
In 646.M32, Agnathio, the Chapter Master of the Ultramarines, unites over 50 leaders from other Chapters of Space Marines and arrives upon Terra. Such a show of power and faith puts an end to the squabbling for the contentious seats of the High Lords of Terra that has consumed the differing factions since The Beheading. In locked council with the mightiest of Mankind's warriors, such matters were quickly sorted out. None know exactly what was done or said, but when the Space Marines departed back to their far-scattered missions, there once again sat twelve High Lords of Terra. If there was further dissension, none dared speak it aloud.
In 888.M32 the Imperium was consumed by the event known as the Astropath Wars. There is no further information on this conflict available in Imperial records.
In 910.M32 the event known as The Firestorm unfolded. There is no further information on this conflict available in Imperial records.
Sometime during the 33rd Millennium, the War of the Confessor unfolds when in a particularly violent display, the Adeptus Ministorum exerts its newfound political strength. Many key Shrine Worlds are added to its holdings during this first of many wars of faith to come.
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 initiating a costly civil war, so he is instead despatched 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 313.M33 the Siege of Eternity's Gate unfolds.
In 615.M33 the Blade of Infinity, a pre-Heresy Cruiser, emerged from the Warp, its re-entry signature suggesting that it had left realspace over 20,000 standard years before. This period predated even the Warp-Drive's invention in the Age of Technology and suggested a radical time stream disorder. Vox transmissions picked up the from the vessel suggested that the Blade of Infinity was trying to communicate some type of warning, but before much could be deciphered, the ancient starship disappeared once again into the Warp. In its wake arrived an invasion fleet of Chaos Space Marine Legions, the Archenemy of the Imperium who wreaked much havoc. The Blade of Infinity reemerged from the Warp several more times in subsequent years, always as a harbinger of further incursions into Imperial space by the Forces of Chaos from the Immaterium.
In 831.M33, during what became known as the Year of the Ghosts, the honoured dead rose up in the Segmentum Solar to drive back the terrors of the Warp.
Sometime during the early years of M34 a great threat to the Imperium arises beyond the Ghost Stars. Even today, its true nature remains suppressed. The ravages are said to cause the extermination of a score of Space Marine Chapters and souls unnumbered. Much of the extant evidence relating to this threat has been censored or purposely destroyed by the Inquisition, but there are contradictory indications which describe the nature of the threat as both a "star-spawned plague" that swept away scores of worlds and to "Nightmare Engines" that slaughtered the populations of whole sectors. This threat is remembered only as the Pale Wasting.
In 401.M34 the terrible crisis 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 while it also distorted the beacon of the Astronomican. Millions of starships were lost in the resulting upheaval and entire Sub-sectors of the Imperium slid once more into barbarism without the dictates of the Adeptus Terra to guide them. It is a terrible price to pay for victory.
Following a fierce Warp Storm bursting from the Eye of Terror in 666.M34, the first of many Warp Stars are sighted. The tendrils of their power pulled any starships or small planets that fell within their reach to a grisly, if spectacular, doom.
In 934.M34 came the Warnings of the Craftworld Ulthwé to the Imperium.
The Nova Terra Interregnum (c. M35)
The Nova Terra Interregnum is also known as the Time of the Twin Empires and was a troubled period in Imperial history when the Imperium of Man fractured for a time into warring factions for over 900 standard years during the mid-34th through the late-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.
During the dark days of the Nova Terra Interregnum, this period in human history of division and civil war fractured the Imperium into a number of different warring factions. The Adeptus Mechanicus was also affected during this Interregnum by division and internal warfare brought about by doctrinal differences and competing centres of power. One of the most discordant of these conflicts was the Moirae Schism which occurred sometime in M35, a dogmatic battle between the Martian Orthodoxy of the standard Cult Mechanicus and a far more radical creed based upon the prophetic writings of a triad of tech-mystics from the minor Forge World of Moirae. The Moirae Schism was one of the most divisive and widespread doctrinal conflicts to afflict the Adeptus Mechanicus since the Horus Heresy. Moirae was eventually blasted into dust, but not before heretical writings from that world spread like wildfire through the domains of the Mechanicus even after Moirae was reduced to a cinder by the Fabricator-General of Mars' rectification fleet, but not before the schism spreads throughout the Cult of Mars, the Titan Legions and several Space Marine Chapters with close ties to the Adeptus Mechanicus such as the Iron Hands. Over 2,000 Terran years of bloody strife pass before the baleful doctrine is considered purged.
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 where political differences would be submerged by usurping 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 of Nova Terra 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 billions died in these religious wars and the power of the Ecclesiarchy had been increased throughout the Imperium to a dangerous level as a result.
In 980.M35 the galaxy suffered from the onslaught of the massive Hrud Rising.
In 991.M35, the 21st Founding, later known as the Cursed Founding, occurs. The Cursed 21st Founding was the largest Founding of Space Marine Chapters since the Second Founding following the Horus Heresy. It had taken place in the 35th Millennium shortly before the start of the Age of Apostasy. Upon the world of Inculaba, a secret geno-lab was the site of the secret project known as "Homo Sapiens Novus," where Mechanicus Genetors attempted to perfect and remove the existing, identified deficiencies in flawed Astartes gene-seed, and ultimately begin the production of new and improved Primarch-like Space Marines. But their project was doomed to failure as the Genetors proved far less skilled in the genetic sciences than the Emperor of Mankind, and their efforts resulted in the development of seriously flawed gene-seed that was used to craft the organ implants for the new Chapters. Worse still, some of these Chapters have developed unexpected genetic idiosyncrasies, mutations that strain the tolerance of the Inquisition and threaten the Chapter's survival. The most seriously afflicted Chapters suffer the wrath of the Grey Knights after they are called in by the Inquisition to expunge the threat. Some escape this fate and flee, eventually turning Traitor and swearing themselves to Chaos.
In 104.M36 the War of Recovery unfolded when patchy reports of technological wonders on the planets of the Mortuam Chain reach Mars. Hoping that it might be possible to recover new STC databases, the Adeptus Mechanicus launched an expedition which began an escalating war that lasted for over a standard century. Aided by the advanced weaponry they recovered, the forces of the Mechanicus freed the human colonies of the region from xenos occupation and several first generation copies of STC databases concerning certain technologies were returned in triumph to Mars.
The Age of Apostasy (M36)
Foreshadowed by the deep political divisions of the Nova Terra Interregnurn, a new age of dissent and power struggles cosumed the Imperium in the 36th Millennium. Zeal eclipsed reason, and misrule reigned supreme. The word of the Emperor was subverted wholesale by corrupt ideologues, each struggling to usurp total control of the Emperor's realm for themselves. This era is known as the Age of Apostasy, a time of brutal Imperial civil war, and is considered to be one of the bloodiest times within the Imperium's history after the Horus Heresy. Around 200.M36, the Age of Apostasy is marked by the Reign of Blood, when the High Lord Goge Vandire, an insane tyrant, became both the Ecclesiarch of the Adeptus Ministorum and the High Lord of the Adeptus Administratum through bribery, blackmail, coercion and murder. During Vandire's Reign of Blood, multiple wars of faith were fought as Vandire attempted to gain control of the Imperium. The Reign of Blood lasted for 70 Terran years before a messenger delivered the news that heralded its end. On the world of Dimmamar, a man named Sebastian Thor and his sect of the Imperial Cult, 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 transformed into the Adeptus Sororitas, the Sisters of Battle, the armed forces of the Ecclesiarchy and the Chamber Militant of the Inquisition's new-formed Ordo Hereticus. The Ordo Hereticus was intended to root out the internal enemies of the Imperium, watch over the Ecclesiarchy and prevent the emergence of another Goge Vandire who sought to serve his own selfish ends rather than the will of the Emperor.
In 310.M36, 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 entire worlds and sector-spanning 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 Plague of Unbelief came to an end after the heroic sacrifices of the Imperial Saint known as the Great Confessor, Dolan Chirosius, who willingly martyred himself on Gathalamor. Chirosius' example proved so potent a display of faith in the God-Emperor that the entire population of the world rose up and cast down Bucharis, restoring Imperial rule and the orthodox faith of the God-Emperor.
In 754.M36 the Imperium was struck by the Web of Intrigue Disaster. There is no further information in Imperial records concerning this event.
In 989.M36, as the Eye of Terror and other Warp rifts visibly expand, the Tech-priests servicing the Golden Throne demand an increase in the number of psykers needed to fuel the Emperor's growing appetite and maintain the Astronomican. The Black Ships increase in number and the frequency of their voyages to collect their tithes of psykers from across the Imperium. According to some records, four times the number of psykers are sacrificed daily to maintain optimal levels of power to the Golden Throne.
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 defences 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.
In 010.M37 the Wrath of the Chaos Sun fell upon the Imperium when the red giant star at the heart of the Maxil Beta System explodes in an expanding cloud of Warpflame. The inhabitants of every world for hundreds of light years are either mutated beyond recognition or possessed by the denizens of the Warp. In response, the High Lords of Terra ordered the mobilisation of whatever Imperial forces were close at hand. So it is that the Grey Knights are joined by a dozen other Chapters, countless Imperial Guard regiments and the nascent Orders Militant of the Adepta Sororitas. The resulting battle does much to heal the remaining wounds in the Imperial body politic that had been opened by Goge Vandire's treachery.
In 020.M37, the High Lords of Terra, in their mercy, begin a systematic and deadly purge within the ranks of the Adeptus Terra and on many worlds across the galaxy to ensure that such a corruption of faith as occurred during the Reign of Blood can never happen again. This becomes known as the Great Cull.
Among the most devastating of the conflicts unleashed during the Age of Redemption were the Abyssal Crusade and the Occlusiad War. 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, rogue Tech-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 psychically prescient leadership the Apostles were swiftly overcome and their weapons hidden away in the vaults of Mars.
By 754.M37, on thousands of planets, menials rebel against their dreary drudgery with wild-eyed leaders espousing a better way of life -- a galaxy of tolerance. The movement is especially popular amongst the youth of the Imperium, earning it the title of Children's Crusade. Billions of earnest pilgrims are lured to seek transport to Terra; some are waylaid by pirates, but the majority disappear into the Warp. They became known collectively as the Lost Crusade.
In 956.M37 the Heavenfall Massacres unfolded. Little else is known about them in the Imperial records.
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 possessed the inviolable military strength required to restore Imperial control in the more lawless regions of the galaxy.
Having purged more than 400 worlds within the Eye of Terror, the survivors of the Abyssal Crusade returned to Imperial space in 112.M38. Without pausing to claim the honours due for such a successful and protracted Crusade, Chapter Master Konvak Lann of the Vorpal Swords declares the now ancient Saint Basillius a false idol and adoration of him tantamount to betrayal. In less than a standard year, every known sepulchre and shrine dedicated to the false saint is destroyed. After his execution, his bones, along with countless relics, books of doctrine and thousands of living worshippers, are placed on a derelict bulk-freighter and launched directly into a nearby star.
During the Grim Harvest in 666.M38, a great armada of misshapen Space Hulks drifts out of the Warp near Terra. Some of the twisted and fused starships can still be identified as transports carrying pilgrims from the Lost Crusade. The Inquisition works feverishly to cover up the fleet's existence and its cargo of mutant and daemon-possessed abominations.
In 001.M39 the Conflict of Helica unfolded.
In 103.M39 the Mausolean Cataclysm struck the Imperium.
In 131.M39, the Redemption Crusades begin. In each of the Segmentums of the Imperium a great hero emerges. Like unto the Primarchs of old are these warriors, and the combined efforts of their Crusades push back the borders of the Imperium further than they have been for nearly 500 standard years. And then, 50 Terran years later, the five heroes vanish without a trace, spurring Ecclesiarch Inovian III to declare them Imperial saints returned to the Emperor's side.
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. In 139.M41, 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, Renegade Chapters, daemonic hosts and rebellious Chaos Cults 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. On the Imperial side, dozens of Space Marine Chapters, nearly 100 Imperial Guard regiments and the better part of three Titan Legions take part, along with every naval vessel the Battlefleet Obscurus can muster. The conflict 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.
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 seven 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 collapsed into rivalry and civil war. The Macharian Heresy, as this time is now known, lasted for seventy standard years and was only ended through the combined efforts of one hundred Space Marine Chapters.
In 500.M41, in an event known as the Tears of the Emperor, the Imperium was swept by visions of the Emperor's tears. From backwards feral planets to the most densely populated Hive Worlds, a million versions of the same story are told by holy men, street agitators, shamans, priests, and mystics. Primitives point to storm-filled skies, claiming that the drops falling from them are the tears of their mighty god. Upon Ecclesiarchy Cardinal Worlds, Arch-Deacons to lowly pilgrims claim to have seen statues of the divine Emperor shed tears. Chapter Masters and hive city urchins alike have visions of the Emperor stirring upon his throne, tears running from his empty sockets. Although the dreams take myriad forms, all know that the Emperor weeps not for himself, but for the plight of Mankind.
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. Zealots rant that the xenos are Mankind's punishment, his just consequences for straying from the Emperor's guidance. The rise of mutants and witches is yet another sign of humanity's sin. Desperate messages from across the galaxy echo through the Warp. Astropaths work feverishly to pull the transmissions from the Immaterium and transalte them, to sift the meaning from the garble. The messages are increasingly dire: Planetary Governors send desperate pleas for aid, Imperial Guard officers call for reinforcements, fleet commanders issue ominous warnings of enemy starship movements. The forces of the Imperium fight with the valour of ancient heroes, defending humanity from within, without and beyond -- but they cannot be everywhere at once.
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. The news grows worse daily, the attacks on the Imperium steadily increasing. Most ominous of all, the prescient foretell of great ripples in the Warp, like a swell in the water disturbed by some colossal but unseen menace in the depths below. Fell things are gathering in that dread realm, straining as never before to break the bounds of reality.
This is surely humanity's darkest hour...
The Imperium made official first contact with the Tau during the Damocles Gulf Crusade, also called the Damocles Crusade, which was the first military conflict fought between the Imperium of Man and the rapidly expanding Tau Empire in the Lithesh Sector of the Ultima Segmentum in the galaxy's Eastern Fringes during the late 41st Millennium. The conflict essentially ended in a stalemate, as the Imperium was forced to conclude its military offensive early to deal with the encroaching Tyranid threat while the Tau sought to begin diplomatic negotiations with the Imperium to show humanity the benefits to be had by accepting the Greater Good. Members of the Tau Water Caste had established trade agreements with Imperial worlds on the frontier of the Tau Empire, near the Damocles Gulf region of the Ultima Segmentum in the galactic east, and exchanges of goods and technology were common. Alarmed by the threat of alien contamination, the Administratum readied a suitable response and almost a century later, the Damocles Crusade smashed into Tau space, destroying several outlying settlements and pushing deep into the Tau Empire. When the Imperial fleet reached the Tau Sept world of Dal'yth Prime, however, the Crusade ground to a bloody stalemate as the formidable numbers and high technology of the Tau and their Kroot allies thwarted every attempt to capture the world or its star system. Many months of terrible fighting ensued with nothing gained on either side. By late 742.M41 the Crusade's commanders eventually agreed to requests from the Water Caste for peace talks. The negotiations were successful and the Imperial fleet withdrew from Tau space unmolested, primarily due to the impending approach of the Tyranid Hive Fleet Behemoth.
The Time of Ending earned its name 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, but the doomsayer's cry is picked up by other psychic sensitives on planets beyond count across the human-settled galaxy.
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 bold deeds done during the Battle of Macragge are one of the most enduring of the many legends of the Ultramarines. The immediate threat presented by Hive Fleet Behemoth is ended under the guns of two entire Imperial Navy battlefleets.Still reeling from the terrible wounds, Imperial Commanders across the Ultima Segmentum look to their borders with growing unease.
The Blood Star Campaign unfolds in 748.M41, when the star Ares turns blood red. It heralds increased daemonic activity in the Scarus Sector. Before the brutal campaign ends, it claims untold lives, including three Chapter Masters and the Fleet Admiral of Segmentum Obscurus.
In 750.M41 the Great Exodus occurs. A strange swirling phenomenon in the Argos System is only a curiosity until the sudden appearance of six Eldar Craftworlds. By the time the Imperial Fleet arrives, both the swirling mass and the Eldar are gone, yet in their passing all prime suns within sixty light years are extinguished. The Imperial Fleet and innumerable transports attempt to ferry the countless billions of Imperial citizens to neighbouring star systems, in what is the largest exodus ever attempted by the Imperium. It is estimated that nearly 12% of the population and 32% of the heavy industry of the region are safely removed. The ring of dead planets and suns is now known as the Deadhenge, a salvager's paradise and refuge of pirates.
The year 757.M41 saw the first recorded incidence of the dread Zombie Plague erupting 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, contagious and mindless undead children of Nurgle.
In 766.M41, many Imperial watch stations and listening posts in the Catachan and Ryza Systems are attacked by Eldar pirates under the command of Yriel. Without their early warning "eyes and ears," this leaves both star systems vulnerable for decades to come.
In 783.M41 Eldar from the Ulthwé Craftworld destroy a Mechanicus Explorator fleet above the Dead World of Maedrax, but not before several probes have been released. Space Marines from the Blood Angels Chapter are dispatched to investigate the loss of the fleet and instead become embroiled in a battle between the Eldar and the Necrons who had just recently awakened on Maedrax.
An uprising in the Krandor System in 795.M41 is harshly put down by the 23rd Cadian Regiment. Several of the Chaos Cults involved in the rebellion, notably the followers of the Shining Deity, the Cult of Many Tentacles and the red-robed Brotherhood, had not been seen since the Fourth Quadrant Rebellion. Although both military and civilian losses are high, the Krandor Rebellion's quick subjugation is vital. The Imperium could ill-afford to lose the resource-rich Krandor System, which held planets strategically vital to the whole of the Segmentum Obscurus.
Throughout the Segmentum Ultima, in 797.M41, countless Ork invasions threaten to mass into a single colossal WAAAGH! The forces of the Imperium are stretched to their utmost to contain each individual war zone. Notable actions include Marneus Calgar, Chapter Master of the Ultramarines, holding the gate alone for a night and a day against the Greenskin hordes during the Siege of Zalathras and the 2nd Company's utter devastation of Warboss Brug's planetary stronghold.
In 801.M41 a brief flicker in the Astronomican throws thousands of ships off course, dooming them to destruction in the Warp. The incident indicates that the Emperor may be weakening.
The lamentable campaign known as the Siege of Vraks occurs from 813-830.M41. The Apostate-Cardinal Xaphan leads the Armoury World of Vraks Prime into the service of the Ruinous Powers. As the forces of the Imperium arrive to quell the rebellion, they are immediately met in battle, followed by a rapid escalation of forces on both sides. The seventeen-year-long campaign ends in a full-scale daemonic incursion and, finally, the intervention of the Ordo Malleus and the Grey Knights. By the end, Vraks is entirely laid waste, its entire population exterminated.
In 822.M41 the Chaos Warmaster Abaddon the Despoiler raids the Eldar Maiden World of Ildanira, seeking a long-lost Chaotic artefact. He is driven away by the forces of the Alaitoc Craftworld. Such an action is only minor compared to the many wars consuming the galaxy at this time, but its portents loom large in hindsight.
By 853.M41, the uprising against Imperial rule on Krandor III, thought to have been successfully suppressed over fifty standard years previously, had once more grown strong. Mutants, psykers and all manner of outcasts had been nurtured in darkness and corruption by the whisper of cowled Chaos Cultists. Even as the surging rebellion takes over the planet's surface, hive city by hive city, the orbital sentinel stations and moon-based defence lasers are captured by Chaos Space Marines accompanied by loathsome creatures, neither man nor mutant but wholly daemonic. Three Space Marine Chapters, led by the stoic Imperial Fists, secure resources, Imperial artefacts and a few Adeptus Administratum officials before an Exterminatus is mercifully delivered. Some 42 Imperial Guard regiments from Krandor III still exist, the only survivors of their lost and benighted world because they had been shipped to distant war zones before the rebellion began.
In 863.M41 the Saint Cyllia Massacre occurred when the Adamant Fury Titan Legion betrayed the Emperor and fell to Chaos. The Traitor Titan Legion turned its guns upon Loyalist regiments of the Saint Cyllian Planetary Defence Forces before making good their escape off-world. The loss of a full Titan Legion sends ripples of concern through the Imperium and great effort is exerted to find and destroy them, particularly by the Mechanicus and its Collegia Titanica.
In 876.M41 Chaos came to the world of Van Horne in the event later known as The Bloodtide to the Inquisition. The Bloodthirster Ka'jagga'nath, Lord of the Bloodtide, broke free of his bonds and unleashed a tide of gore that corrupted everything it touched. For eight days and nights, the orgies of blood continue, each fresh death luring yet more daemons to the mortal world as the barrier between the Materium and the Warp breaks down. Only when the Grey Knights' 4th Brotherhood arrived was the Bloodtide abated, and then only at great cost. Ka'jagga'nath is cast back into the Warp. The psychic backlash also banishes the Bloodtide and the daemons it had drawn forth.
In 883.M41 the 423rd Cadian Regiment's spearhead, led by Knight Commander Pask, was the largest armoured assault undertaken by the Imperium since the Tallarn during the Horus Heresy. Over 8,000 Imperial tank companies and 35 super-heavy tank detachments were annihilated during the nearly the nearly total destruction of the Renegade Adamant Fury Traitor Titan Legion upon the Planus Steppes.
In 891.M41 the worlds of Persya suffer attacks from Eldar Corsairs during the Long Midnight who swathe their targets in utter darkness before pillaging and salughtering at will. The vicious raids only cease upon the arrival of the Praxion Patrol.
In 897.M41, the fortress-convent known as Sanctuary 101 is destroyed, with all the Sisters of Battle within, by the Necrons. No survivors or signs of the perpetrators are left behind. Some few savants in the Imperium begin to understand the vast threat that the awakening Necrons might become to Mankind.
In that same year, 897.M41, a new Tyranid menace, code-named Hive Fleet Gorgon, is spotted by Imperial outposts, heading directly for the growing Tau Empire in the Eastern Fringe. No warnings are given to the Tau of what is to befall them.
In 901.M41 the terrible civil conflict known as the Badab War begins when Lufgt Huron, the Chapter Master of the Astral Claws Space Marines, refuses to hand over his Chapter's tithe of gene-seed to the Administratum and instead announces his secession from the Imperium, declaring himself the Tyrant of Badab. Twelve standard years of intersystem war follow, wreaking havoc on shipping lanes in the Maelstrom Zone and embroiling more than a dozen Space Marine Chapters. With much loss, Badab Primaris finally falls to the Loyalist forces, but Lufgt Huron and some 200 of the Astral Claws escape to take refuge in the Maelstrom of the Ultima Segmentum. There, they become Chaos Space Marines and change their name to the Red Corsairs. They become dreaded pirates and raiders of Imperial commerce. Huron adopts the title of Blackheart and continues to recruit more Astartes Renegades to join his growing Chaotic empire.
In 907.M41 Ork WAAAGH! activity rises throughout all five Segmentums of the Imperium, forcing the Novamarines, Raptors and Howling Griffons to be redeployed away from the Badab War to counter the growing Greenskin threat.
In 920.M41 Eldar pirates attack the advance Escort of a fleet of Black Ships as they exit Warpspace in the Thanos System. The pirates destroyed three Frigates and captured the troopship Emperor's Faithful, the pirates quickly disappeared, taking with them a vast complement of Imperial Guard and Imperial Navy personnel. As a result, the fleet of Black Ships is left vulnerable and is picked off one by one in further raids.
In 926.M41 during the Vaxhallan Genocide, a Chaos Space Marine warband known as The Purge slaughtered over 14 billion Imperial citizens and claimed the planet Vaxhall as their own. Vaxhall served as an Astropath relay hub and as an Imperial Fortress World, the buttress of the Herakles System.
In 937.M41 Inquisitor Pranix lead 5 companies of Space Wolves and units of the 301st Cadian and the 14th Tallarn Imperial Guard regiments in an attempt to reclaim the 9 Hollow Worlds from the clutches of the Chaos Lord Huron Blackheart and his Red Corsairs warband. The Imperium's forces are stunned to see how quickly the Red Corsairs have expanded and how vast their Renegade empire of pirates has grown.
In 941.M41 the Second War for Armageddon began when the largest and most powerful Ork in millennia, the Warlord Ghazghkull Mag Uruk Thraka, leads a vast WAAAGH! that, after much rampaging, meets its match upon Armageddon, a Hive World of vital strategic importance to the Imperium in the Segmentum Solar. The Orks are defeated only by the stubborness of the defenders, the combined might of three Space Marines Chapters and the legendary heroics of Commissar Yarrick. Ghazghkull escapes and vows to return one day.
In 963.M41 the Imperium ran afoul of 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 Ultramarines' Chapter Master Marneus Calgar, but he generously allows the Tau to evacuate before the surface of the planet is destroyed. The planet's destruction sets off a brief flicker of unknown energy on dozens of planets throughout the galaxy. Many fear that more Tomb Worlds are awakening. 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 Necrons who seek to reestablish their galaxy-wide empire of ages past.
In 969.M41 the ancient starship Blade of Eternity is once again sighted, this time near the Cando System. As it is approached, the ship is mysteriously replaced by the infamous Death Guard Plagueship Terminus Est. The Zombie Plague sweeps across the system. Infected refugees carry the Chaotic foulness far and wide across the Imperium.
In 973.M41 a violent Warp Storm troubles the dreams of men across the galaxy -- for those more psychically aware, the storms prove catastrophic. Nightmares crack the barrier between realspace and the Warp, slaying many psykers and creating rifts between the Immaterium and reality. Although brief, thousands of daemonic incursions cause untold damage and many dark seeds of corruption are planted.
In 975.M41 the Bloodthirster Skarbrand materialises on the Cadian Fortress World of Lutoris Epsilon. His berserk rage infects all he surveys and soon the fortifications are drenched in blood as the Imperial Guardsmen turn upon each other in crazed bloodlust. Lutoris has since been considered cursed and is currently classified as a quarantined Forbidden World by the Inquisition.
In 976.M41 a massive Ork invasion smashes into the western sector of Segmentum Ultima. WAAAGH! Grax is denied taking the Forge World of Ryza, but the surrounding sectors suffer great devastation.
In 989.M41 WAAAGH! Snagrod rampages across the Loki Sector, culminating in an assault on Rynn's World that nearly wipes out the venerated Crimson Fists Chapter of Space Marines when an unfortunate accident destroys their fortress-monastery. Imperial forces retake the Agri-world in 991.M41 and the Crimson Fists begin the long process of rebuilding the Chapter back to full strength.
In 992.M41 Eldar forces attack Cadian holdings on the world of Aurent, only to be utterly defeated through the inspired tactical genius of Ursarkar E. Creed.
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 simultaneously 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 138.997.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 in what is sometimes called the Third Tyrannic War. It becomes clear that the two previous Tyranid incursions into the galaxy were only reconnaissance expeditions for the main Hive Fleet.
In 221.997.M41 the world of Piscina IV is invaded by Orks under the joint leadership of Ghazghkull Thraka and the Bad Moons clan Warboss Nazdreg. Orkish teleportation technology is employed in a surprise attack and only the stout defence command by Master Belial of the Dark Angels Chapter and the timely arrival of reinforcements ends the Ork threat. Although the Imperial victory is great, several Imperial commanders, including Belial, feel that Ghazghkull has another trick up his sleeve.
In 509.997.M41 elements from the Ultramarines and Mortifactors Space Marine Chapters make a stand against one spur of Hive Fleet Leviathan on the world of Tarsis Ultra. The defenders defeat this tendril with the use of a genetically-engineered biological plague, but the remainder of the enormous Hive Fleet rampages on unaffected.
In 601.997.M41 Ghazghkull Thraka comes face-to-face with his old human nemesis, Commissar Yarrick, on the battlefields of the world of Golgotha. Yarrick is captured by the Orks but ultimately released as Warlord Ghazghkull is planning to invade Armageddon once more and wants to ensure a good fight. Greenskins flock to Ghazghkull's WAAAGH! in every greater numbers.
In 977.997.M41 the small but vibrant Tau Empire begins its Third Sphere Expansion. The Tau forcibly capture half a dozen more Imperial worlds on the Eastern Fringe and several more join the Tau Empire willingly to serve their Greater Good.
In 757.998.M41 Ghazghkull finally returns to Armageddon for his long awaited rematch in the Third War for Armageddon at the head of a new, even greater Ork WAAAGH!. Ghazghkull has further perfected the teleportation technology that he experimented with on Piscina IV and begins the campaign with devastating victories over the Imperial defenders. Imperial Commanders, having learnt from their previous encounters with this wily Ork Warlord, commit massive numbers of troops and quickly send out the call for nearby Space Marine Chapters and further reinforcements. Several months into what rapidly becomes a battle of attrition, Ghazghkull grows bored with the grinding stalemate and leaves his minions behind to finish the fight while he sets off to conquer the surrounding planets. He is pursued by Commissar Yarrick and the Black Templars, who swear an oath to finally bring the Greenskin to heel.
In 718.999.M41 Hive Fleet Leviathan invades the large Ork empire based in the Octarius System. War between Tyranids and Greenskins rages on with no signs of stopping. Imperial Navy scout patrols keep a close eye on the conflict, for should a victor emerge, there are precious few forces of the Imperium on hand to counter whchever enemy should arise out of the sector-wide bloodbath.
In 884.999.M41 the Dark Angels' 5th Company battles elements of the Crimson Slaughter Chaos Space Marine warband for the control of the artefact known as the Hellfire Stone. The Nephilim Sector trembles as the hated foes clash...
In 975.999.M41 the light of the Astronomican grows noticeably dimmer, while contact is lost with Ultima Macharia and is intermittent with Macragge and Cypra Mundi. Some Imperial savants theorise that this is because of delays and losses amongst the Black Ships, while others point to omens of impending doom and the weakening of the Emperor.
In 980.999.M41 the Red Corsairs launch a major raid from out of the Maelstrom, bringing the Chogoris, Kaelas and Sessec Systems under siege. Rumours report Huron Blackheart has grown his group of Renegades as large as the full Space Marine Legions of ancient times. The Chaos Lord now wields military power unseen since the time of the Heresy.
In 982.999.M41 The Great Awakening occurs, when a ripple of psychic activity passes through the Imperium, awakening the dormant powers of countless latent psykers. The resulting backlash creates innumerable Warp rifts and a thousand worlds are lost, hopelessly embroiled in daemonic incursions.
In 987.999.M41 the Necrons rise to strike the Cypra Segentus System -- the first recorded Necron attacks within only 2,000 light years of Terra.
In 989.999.M41 the Ultramarines' 3rd Company liberates the Lagan System from the Tau Empire during the conflict known as the War of the Rising Sons. Even while they do so, several key worlds of the neighbouring Dolmac System capitulate without firing a shot to Tau ambassadors and join the Tau Empire.
In 990.999.M41 the Devastation of the Octarius Belt occurs when Eldar from the Biel-Tan and the Saim-Hann Craftworlds assault many worlds surrounding the Octarius System with the intent of denying crucial biological resources to Hive Fleet Leviathan. Many are ork-held worlds, but quite a few were colonised by the humans of the Imperium. The loss of human life is substantial, as is the loss of tithes that the planets would have paid to the Imperium in its time of need.
In 992.999.M41, the Night of a Thousand Rebellions occurs. Uprisings and discord strike countless planets across the Imperium. Unrest races like wildfire, consuming many outlying planets, but also supposedly secure worlds like Enceladus, Darkhold, and Minisotira. Even the homeworld of the Lions Defiant Space Marine Chapter is lost to anarchy caused by secret cults and frenetic agitators. Contact is lost between Terra and large swathes of the Segmentum Pacificus.
In 993.999.M41, wave after wave of Astropathic pleas for help flood at once from all across the galaxy, though there is only an eerie silence from the Segmentum Pacificus. So powerful is the influx, so overbearing is the psychic current, that the Adeptus Astra Telepathica suffers serious personnel losses amongst their Astropaths. Whole choirs collapse at once, driven mad or slain outright, their minds bursting. Vast breakdowns in Imperial communications ensue, increasing both anarchy and panic as the endless psychic screams for help echo across time and space.
In 995.999.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 surrounding worlds of 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 forces of the Chaos Gods read like a roll call from epic battles of past ages. Always in the vanguard are the Black Legion, followed by the Death Guard, World Eaters, Alpha Legion, Thousand Sons, Night Lords and others from the annals of the Imperium's blackest days. Legions and Renegade Chapters of Space Marines long thought extinct renew their assaults on the realm of the hated Corpse Emperor. Before them run infected, plague-ridden Chaos Cultists, deranged mutants and traitorous scum in numbers too great to be counted. Behind them tower Daemon Princes, Daemonhosts and other Warp creatures eager for the slaughter to be found in the mortal realm. Astropaths everywhere cringe to open their minds to receive messages, for the Empyrean rings with mind-splitting peals, possibly the sound of the myriad tears ripping in the barrier between the Materium and the Warp, or perhaps it is simply the laughter of the Dark Gods. 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. Astropaths everywhere cringe to open their minds to receive messages, for the Warp rings with mind-splitting peals, possibly the sound of the myriad tears ripping in the barrier between the material world and the Warp, or perhaps it is the laughter of Dark Gods.
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 Astronomican 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 learned a terrifying secret in 986.999.M41: 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...
- Warhammer 40,000 Rulebook (6th Edition), pp. 168-177
- Warhammer 40,000 Rulebook (5th Edition), pp. 122-129