The Age of the Imperium is the name given by Imperial lexographers and Historitors 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 30th 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 and together the two most populous worlds of humanity birthed the Imperium of Man.
Using the advanced technology of the Mechanicum, 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 (ca. M29 - 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, constant strife, and chaos. When the storms abated with the emergence of Slaanesh in the Warp in the late 29th Millennium, 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 created 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 ascendancy would come a rebirth of civilisation and government with the Emperor founding an all-embracing civil administration to order and rebuild His world, a program to cleanse the human population of centuries of genetic damage from the use of nuclear, alchemical and biological weapons of mass destruction, and concentrate such knowledge that could be salvaged from the dust of ages in newborn houses of learning and education. The unification of Terra would only be the start of His plan to revive the human race.
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 called the Treaty of Olympus Mons by the Mechanicum. This was the formal name given to the binding agreements that regulate the coexistence of the Imperium of Man and the Cult Mechanicus. This treaty marked the official birth of the nascent Imperium of Man in the late 30th Millennium. The Treaty of Mars granted political autonomy 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 six Houses of Navigators and Astropaths to the Mechanicum so that it could once more travel the stars to 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 an eagle and lightning bolt, the Raptor Imperialis, 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 had conceived of and created the twenty Primarchs to be His transhuman agents of change and lords of war, 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 the arts 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 by the unified will of the Chaos Gods. 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 early Legiones Astartes, the Emperor first brought the Unification Wars to their successful close and then planned to unleash the Great Crusade intended to reunite all of Mankind across the galaxy beneath His benevolent rule, banishing the violence, superstition and injustice that had afficted humanity throughout the five millennia of the Age of Strife.
Birth of the Astronomican (ca. 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 at the time). 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 by human starships 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 Imperial Sanctioned 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 (ca. 798.M30 - ca. 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 myriad Expeditionary Fleets of the Space Marines, supported by the regiments and starships of the newborn Imperial Army, proved unstoppable. Aliens and Warp creatures were driven back, planets were reclaimed and the missing Primarchs were discovered to have been scattered through the Warp to human-settled worlds across the galaxy.
The Emperor preached three great truths in His reconquest of the galaxy: genetic corruption must be sought out and eradicated as he had done on Terra; psykers were to be rooted out, kept under control, and handed over to Imperial agents for evaluation; and destructive aliens were to be rendered powerless. The Great Crusade lasted for over 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 created the Imperium of Man in the minds and hearts of humanity across the galaxy.
The Horus Heresy (ca. 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 largely as a result of his own growing jealousy and resentment towards his genetic father.
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 fully half of the Space Marine Legions, four Titan Legions and an untold number of formations from the Imperial Army and the Dark Mechanicum) 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 nine 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 marked 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 (ca. 014-021.M31)
The Great Scouring, or simply The Scouring, was the Imperium of Man's great counteroffensive 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 Traitor regiments and starships of the Imperial Army and Imperial Navy that had turned to Chaos were to be destroyed or driven into the Eye alongside their leaders. 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 true start of the ten-millennia-long era known as the Age of the Imperium.
The Second Founding (ca. 021.M31)
In the midst of the Great Scouring campaign, the Second Founding occurred. 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 the Primarch Roboute Guilliman of the Ultramarines 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 realities of an interstellar government where the Emperor was no longer capable of carrying on the day-to-day tasks of rule.
The remaining 9 Loyalist Space Marine Legions were disbanded to form the far smaller 1,000-man organisations known as Chapters, each along with their own supporting spacecraft and planetary fiefdoms in accordance with the established dictates of Guilliman's magnum opus on military strategy and organisation, the Codex Astartes. In the wake of the Horus Heresy and the Emperor's "ascension," Guilliman had become the ruling Lord Commander of the Imperium, the first among equals among the Senatorum Imperialis that now ruled the Imperium in the silent Emperor's name. 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 Imperial Army was divided into the land-based forces of the Astra Militarum and the space-based forces of the Imperial Navy, each with a separate chain-of-command structure and bureaucracy.
Resistance from several Legions to Guilliman's order to break up their Legions, particularly among the Imperial Fists nearly brings the Imperium to another crisis, until the scions of Rogal Dorn suffer through the battle of the Iron Cage and Dorn relents after the V Legion is only saved by the intervention of Guilliman's Ultramarines.
The Imperium suffers a great blow when Guilliman was mortally wounded at the Battle of Thessala in 121.M31 by the Daemon Primarch Fulgrim and is placed in stasis in the Temple of Correction in the fortress-monastery of the Ultramarines, the Fortress of Hera, on Macragge. It becomes a major pilgrimage destination for believers of the Imperial Cult over the next 10,000 years.
The Time of Rebirth (ca. M31 - ca. M32)
During the Time of Rebirth the Imperium of Man slowly recovered from the Horus Heresy, economically, politically and even technologically. 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 as the Emperor had planned. 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.
Rise of the Adeptus Ministorum
The Emperor, always an object of veneration, only increases His following after being joined to the Golden Throne, an act remembered as His "ascension." Many Imperial cults arise over the following centuries, the majority of which are united into a larger body known as the Ecclesiarchy lead by the largest cult, the Temple of the Saviour Emperor. This powerful church gains momentum until, in the 32nd Millennium, it is granted the status of 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 Terran years, the seat reserved for the Ecclesiarch, the church's High Priest, is made permanent. The political power of the Ecclesiarchy only continues to grow as the centuries pass and the people of the Imperium's faith in the God-Emperor becomes ever more intense.
The War of the Beast (544-546.M32)
The Orks rampaged across the Imperium on a massive scale in 544.M32 during what became known as the War of the Beast. The number of Greenskin attacks grew until it became the greatest Ork invasion that the galaxy had ever known to that time, eclipsing even the Ork WAAAGH! defeated by the Emperor and Horus during the Ullanor 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, including several assaults on Terra itself, 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 Orks had developed six massive Warlords known as "The Beasts" by the Imperials, who each created six "Legions" of Orks similar to the ancient Space Marine Legions that had originally defeated them on Ullanor. These Orks were of a different sub-species than other Orks, were much more intelligent and could converse with humans fluently in their own language. They also developed gravitic and teleportation technologies more advanced than anything the Mechanicum had on hand, including the ability to teleport planets through what the Imperials named "subspace." The Orks built so-called "Attack Moons" by using gravitic technology to pull a planet's crust and mantle into space and then reshape it into a sphere. These Attack Moons were armed with "Gravity Whips" that could destroy entire fleets of Battleships with crippling gravity waves.
Three great battles were fought on Ullanor, the site of the ancient Ullanor Crusade and the capital of the new, advanced Ork civilisation and their greatest temple to the Ork gods Gork and Mork, to ultimately kill the Beasts using the aid of captured Ork psykers or "Weirdboyz" and the psychic null powers of the Sisters of Silence. The first of these battles was won by Vulkan, the Perpetual Primarch of the Salamanders Legion who aided the Imperium at this time and kept reincarnating after his death.
After the final conquest of the Beasts on Ullanor, the Mechanicum took over the world to strip away the Ork technologies in an attempt to learn how to teleport planets like Mars through the Warp and gain access to the Orks gravitic weapons. To keep the High Lords of Terra from knowing that they were violating Imperial doctrine to eschew any research into forbidden xenos technologies, the Tech-priests eventually teleported Ullanor into the Segmentum Solar, where it was wiped clean of Ork remains and reopened for human colonisation with a new name -- Armageddon. It is for this reason in the 41st Millennium that the Orks continually returned to claim the planet, never realising it is actually the home of their greatest empires of old.
The War of the Beast brought many structural changes to the Imperium. The Inquisition was first divided into the Ordo Xenos and the Ordo Malleus at this time, and the Deathwatch, the Chamber Militant of the Ordo Xenos, was founded to face the Orks during the conflict. The position of Lord Commander of the Imperium, first among equals among the High Lords of Terra, was finally abolished and the Captain-General of the Adeptus Custodes was granted a seat on the High Lords' Senatorum Imperialis. In the wake of their near-destruction during the war, the Imperial Fists Chapter, long the sentinels of the Imperial Throneworld, left Terra behind, instead committing themselves to a never-ending Crusade against the foes of Mankind using their mobile fortress-monastery, Phalanx.
The Beheading (546.M32)
The byzantine politics of the Imperium took a calamitous turn in 546.M32 in the wake of the War of the Beast 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 Assassins and veteran political manipulator. A Space Marine retribution force drawn from the Halo Brethren, Imperial Fists and Sable Swords Chapters tracked the Grand Master to an Officio Assassinorum 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 under the aegis of the Adeptus Astartes.
The Forging (ca. M32 - ca. M34)
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 astro-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.
At some time in the 33rd Millennium, the War of the Confessor unfolds when in a particularly violent display, the Adeptus Ministorum exerts its newfound political strength in the wake of the War of the Beast. 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 solar 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 Heretic Astartes Traitor 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.
Sometime during the early years of the 34th Millennium a great threat to the Imperium arises beyond the Ghoul 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.
A stele mounted within the Imperial Palace on Terra recognises the services of the Novamarines for their action against the Pale Wasting that occurred in the 34th Millennium. This artefact praises the Chapter and credits their work for having "unmade that which cannot die." This campaign was where the Novamarines earned some of their earliest recorded battle honours. Those partial records which have been uncovered suggest that the threat was xenos in nature and that more than one Space Marine Chapter may have been completely destroyed in the course of the conflict. The Novamarines took part in the campaign to quell the threat of the Pale Wasting, and though this is one of the Chapter's earliest recorded battle honours, the Chapter's own chronicles are curiously empty of any reference to this conflict. Were it not for such prominent recognition, the incident might be completely forgotten.
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 proves 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 (ca. M35 - M36)
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 early 35th through the early 36th 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.
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 the 35th Millennium, 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 spread 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 more of bloody internecine strife within the Mechanicus 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 and uniting all humanity beneath a new theocracy. 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, helping to set the stage for the events of the Age of Apostasy which followed in the 36th Millennium.
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, occurred. 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 individual 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 consumed 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 Master 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 full 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 reformist 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 Astra Militarum 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 by the actions of the Adeptus Custodes 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 Adepta 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.
Sebastian Thor was named the new Ecclesiarch in the wake of the Reign of Blood, and his Confederation of Light's theology replaced the old orthodoxy of the Imperial state church with its emphasis on the need for political control over the Emperor's realm. However, many of those "old believers" went underground, forming a heretical sect known as the "Temple Tendency" that would plague the frontier regions of the Imperium for millennia to come.
In 310.M36, the event known as the "Plague of Unbelief" unfolds and 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 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 reach of 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 after this year.
The Age of Redemption (ca. M37 - M41)
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 Astra Militarum 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 exploded 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 War 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's very existence 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 solar 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 rebelled 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.
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 of the Emperor. 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 began. 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.
The Waning (ca. 001.M41 - ca. 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, xenos infestation 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.
To combat the spreading anarchy, the Adeptus Terra imposed ever stricter rules, doling out ever harsher punishments. Portents of doom were both incessant and relentless. The prescient foretold of great ripples in the Warp, like a swell in the water disturbed by some colossal but unseen menace.
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 that began in the centuries after the Horus Heresy. 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 Astra Militarum 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 two of the Blackstone Fortresses, their future purpose unknown.
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 Worlds 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 (ca. 750.M41 - ca. 999.M41)
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, T'au, 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 translate them, to sift the meaning from the garble. The messages are increasingly dire: Planetary Governors send desperate pleas for aid, Astra Militarum 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 T'au 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 T'au 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 T'au sought to begin diplomatic negotiations with the Imperium to show humanity the benefits to be had by accepting the Greater Good.
Members of the T'au Water Caste had established trade agreements with Imperial worlds on the frontier of the T'au 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 Terran century later, the Damocles Crusade smashed into T'au space, destroying several outlying settlements and pushing deep into the T'au 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 T'au and their Kroot allies thwarted every attempt to capture the world or its star system. Many solar 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 T'au 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, proclaimed 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. These are the last days of the Imperium, but whether glorious apotheosis or eternal damnation awaits, none can say...
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. Chapter Master Marneus Calgar is gravely wounded by the horror known as the Swarmlord, and the Ultramarines' Veteran 1st Company are slain to the last man, but their sacrifice buys time for two Imperial Navy battlefleets to converge upon Macragge and finally end the Behemoth's threat. 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 and a distress hymnal despatched. Some solar months later, Space Marines from the Blood Angels' 3rd Company arrive the fleet's disappearance and becomes embroiled in the ongoing war between Ulthwé's forces and the Necrons that the Explorators inadvertently awoke on Maedrax's surface.
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 Warmaster of Chaos Abaddon the Despoiler raids the Eldar Maiden World of Ildanira, seeking a long-lost Chaos 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 solar 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 on Van Horne. 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 Battle of Tallarn during the Horus Heresy. Over 8,000 Imperial tank companies and 35 super-heavy tank detachments were annihilated during 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 slaughtering 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 T'au Empire in the Eastern Fringe. No warnings are given to the T'au 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 Heretic Astartes 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 Chaos 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 Astra Militarum 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, lead 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 T'au Empire when the Ultramarines clashed with a T'au 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 T'au 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 T'au 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 T'au 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 Chaos 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 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. Though the Orks were finally driven off Rynn's World, Chapter Master Pedro Kantor declines the opportunity for pursuit, instead throwing his efforts into rebuilding the Crimson Fists to their former glory. Snagrod himself escapes, and proceeds to wreak further havoc across the sector.
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 later known as the Second Tyrannic War 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. From Macragge to Ultima Macharia, the forces of the Imperium hurry to confront this new threat, leaving many sectors open to attack by other enemies.
In 221.997.M41 the world of Piscina IV is invaded by Orks under the joint leadership of Ghazghkull Thraka and the Bad Moons klan Warboss Nazdreg. Orkish teleportation technology is employed in a surprise attack and only the stout defence commanded 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 even greater numbers.
In 977.997.M41 the small but vibrant T'au Empire begins its Third Sphere Expansion. The T'au forcibly capture half a dozen more Imperial worlds on the Eastern Fringe near the Damocles Gulf and several more join the T'au Empire willingly to serve their Greater Good. The war has suffered several lulls and escalations and shows no sign of relenting.
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 solar 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, unleashing the Octarius War. The battle 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 whichever 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 T'au 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 T'au ambassadors and join the T'au 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 999.M41 the Blood Angels are tested as never before. A tendril of Hive Fleet Leviathan is judged to be on a direct course for their homeworld of Baal. Worse, the dread Bloodthirster Ka'Bandha returns from the darkness of the Warp with a daemon army at his command, his first blow striking against Ammonai, outermost planet of the Baal System. Faced with a terrible war on at least two fronts, Lord Commander Dante of the Blood Angels makes swift preparation, uniting many Imperial and non-human worlds under the banner of survival. Even some former foes can be counted in Dante's alliance, though whether or not they can be entirely trusted is another matter.
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. After a gruelling campaign with a death toll that spirals into the trillions, Abaddon the Despoiler succeeds in tearing down the strange pylons that for millions of standard years had held the Cadian Gate as a stable region of space by using the damaged Blackstone Fortress Will of Eternity as an artificial meteorite to assault the Fortress World. Despite the best efforts of the Imperium's staunchest defenders -- including the Black Templars, Imperial Fists, Dark Angels and Space Wolves -- the Fortress World of Cadia, lynchpin of the defences surrounding the Cadian Gate, eventually falls and a wave of Warp Storms roars into being across the length of the galaxy. Though reinforcements continue to arrive for both sides, Imperial forces begin a great exodus while battles still rage throughout the sector.
Even as Cadia falls, 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.
With doom looming 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...
The Gathering Storm (ca. 999.M41 - Present)
Strange events, the appearance of the ancient Archmagos Belisarius Cawl and a cryptic alliance with a mysterious Aeldari faction known as the Ynnari conspire to awaken the Ultramarines Primarch Roboute Guilliman from his millennia-long slumber in a stasis chamber during the Ultramar Campaign of the 13th Black Crusade. The Primarch is immediately embroiled in battle as a Chaos assault by the Black Legion as Abaddon attempts to prevent his return, though he successfully drives the servants of the Dark Gods from Ultramar, for a time. Guilliman then embarks upon the successful Terran Crusade through many tribulations to return to Terra and meet with his father the Emperor for the first time in ten thousand standard years. What passes between them is unknown, but when he emerges from the Imperial Palace, Guilliman initiates plans for Imperial survival that he first set into motion in the days immediately after the end of the Horus Heresy.
The Great Rift
Soon after the fall of Cadia, reality tears itself apart from the Hadex Anomaly at the core of the Jericho Reach in the Eastern Fringe, to the furthest star system of the Segmentum Obscurus. From that hole come Warp Storms not seen since the Age of Strife, cutting off the galactic north from Terra. The initial period, known as the Noctis Aeterna -- or the Blackness -- is terrible indeed. For a time, all Warp travel is impossible and the far-spread planets of the Imperium are isolated, with no travel or astropathic communication between them. Worlds in their hundreds fall before the ensuing Chaos onslaught. The pulsing Cicatrix Maledictum spreads like an impenetrable curtain, robbing entire systems of the holy light of Terra. A chain reaction of Warp cataclysms rips across the Imperium, plunging its worlds into disaster and awakening the dormant powers of latent psykers across the galaxy. Countless civilisations are lost to daemonic incursions as the galaxy burns. To those on the Terran side of the rift, it is a tainted scar stretching across the sky. To those unfortunates on the far side, in the region now named the Imperium Nihilus, the "Dark Imperium," it is something much worse -- the very gates of Hell.
No one fully understands the origins of the Great Rift, though there are many theories: the breach of the Cadian Gate during the Despoiler's recent 13th Black Crusade, the sorcery of the Daemon Primarch Magnus the Red during the Thousand Sons' invasion of the Fenris System, catastrophe in the Webway, the birth of Ynnead, the Aeldari God of the Dead, mass bloodshed and fire in the Damocles Gulf, the resurrection of the Primarch Roboute Guilliman -- all may have caused or contributed to it.
The Second Battle of Terra
As the first Warp Storms broke over Holy Terra, its pollution-filled skies turned a roiling crimson. Khorne, heedless of the plans of his brothers and hungry to prove his superiority, sent forth eighty-eight cohorts of his daemon legions to assault the Imperial Palace. The Blood God wanted the glory of tearing down the Golden Throne for himself, and so the skies of Terra congealed into bloodclouds that deployed the Red Host directly before the Lion's Gate.
The gun batteries of the Imperial Palace are second to none, yet they alone could not halt this red tide. Led by Roboute Guilliman, the newly reappointed Lord Commander of the Imperium, the Primaris Space Marines, Adeptus Custodes and Sisters of Silence fought side by side. Although the rash Chaos assault was turned back and broken long before it could reach the Eternity Gate to the Inner Palace, the High Lords of Terra were shaken at the boldness of the foe. Without the beam of the Astronomican, their arcane machinery and protective devices were not enough to halt the fell powers from materialising even on Holy Terra. Khorne, upon receiving the returning forms of his slain, grew so apoplectic in his rage that his fortress in the Realm of Chaos trembled. So great was the heat from his outburst that the essences of the eight Bloodthirsters that led the failed attack were wholly obliterated.
After his defence of Holy Terra, Roboute Guilliman gathered a new armada that he named the Indomitus Crusade, the largest concentration of Imperial military forces seen since the original Great Crusade over ten thousand standard years before. Along with elements of the Adeptus Custodes, a small contingent of the Silent Sisterhood, and a vast war host of Primaris Space Marines from many newly founded Chapters and the Legions of the Unnumbered Sons, the Primarch set a winding course. Strike forces from over a dozen pre-existing Chapters of Space Marines, led by the Imperial Fists, joined the fleet. Thus began many new legends as Guilliman travelled to aid beleaguered planets, breaking sieges and sweeping away Chaos and xenos invaders alike to bring hope back to the desperate defenders. It was not long before word began to spread, as all those planets that could still receive astropathic messages hailed the return of a hero out of myth. Once more, one of the demigods of the past fought for the Imperium of Mankind. The Indomitus Crusade would reach its end over a century into the 42nd Millennium at the Battle of Raukos. Afterwards, Guilliman would turn his attention to helping his Realm of Ultramar defeat the forces of the Death Guard Traitor Legion and the servants of Nurgle in the Plague Wars.
Devastation of Baal
After sacrificing the Shieldworlds of the Cryptus System to fend off the xenos' earliest advance on the Baal System, the planet of Baal itself came under intense attack by Hive Fleet Leviathan. The Tyranid Hive Fleet was of such mass, even after its considerable losses, that it blotted the stars from the skies. Lord Commander Dante bolstered the formidable defences of the Blood Angels' homeworld and its moons like never before. Not one to await attack, he also sent forth scores of preemptive strike forces to delay, mislead, and whittle down the living armada. Hundreds of splinter fleets were thus defeated. Dante's call, beseeching the Blood Angels' Successors to send immediate aid to their parent Chapter, did not go unheeded. The Flesh Tearers were the first to arrive, and ultimately all the Successor Chapters save the Lamenters answered the call. Even the Knights of Blood, who had been declared Excommunicate Traitoris by the High Lords of Terra, arrived to bolster the defences. It was still not enough.
Learning at an exponential rate, Hive Fleet Leviathan could not be thwarted by the same strategy twice. Advancing steadily, their superior numbers cleared the entire surrounding sector of life before the xenos made planetfall upon Baal and her twin moons. The first nineteen waves, each larger than the last, were driven off at great loss to the Blood Angels and their Successor allies. Five Chapter Masters fell in that bitter fighting, three in the Battle at the Dome of Angels alone. The Tyranids began the process of absorbing all biomass from Baal and its moons, absorbing even the radiation-poisoned deserts of Baal Secundus. With their defences in ruin and Baal's moons stripped and broken, the remaining Space Marines retreated back to the rubble of the Blood Angels' sprawling fortress-monastery. There, they prepared for a last stand as the next wave swept downwards. Doom, it seemed, had at last come to the Sons of Sanguinius.
It was then that the Great Rift cracked open the galaxy in the wake of the fall of Cadia to the 13th Black Crusade, and the withered Baal System was blasted by the aetheric storms. Although no further attack waves came from the Leviathan Hive Fleet, not a single Imperial defender remained alive upon the last moon, Baal Prime. On Baal itself there were already enough Tyranids there to destroy the Imperial troops many times over. Even with no chance of victory, Commander Dante led his troops, each fighting retreat seemingly more hopeless than the last. As the final perimeter was broken, the stars reappeared. Looking skywards, the Tyranids on the surface of Baal sought contact with their Hive Fleet, but it was gone, replaced by a newly arrived Imperial fleet. Like an angel of vengeance came Roboute Guilliman and his Indomitus Crusade. After many more battles, Baal was finally cleared of the xenos threat. A great rebuilding of both world and Chapter was undertaken, for the Blood Angels and their Successors were sorely needed elsewhere in the beleaguered Imperium. What became of the Leviathan is a mystery, although a clue was found upon the now-barren moon of Baal Prime. Xenos skulls were piled impossibly high in the much-reviled, eight-pillared symbol of one of the Blood Angels' most terrible and ancient nemeses: the Bloodthirster Ka'Bandha and his army of Khornate daemons.
The Plague Wars
The Plague Wars were an attempt by the daemonic and Heretic Astartes forces of the Chaos God Nurgle, including the Daemon Primarch Mortarion and his Death Guard Traitor Legion, to conquer the Realm of Ultramar and add it to the Plague God's growing realm in realspace. The Plague Wars began at some point after the birth of the Great Rift and the onset of the Noctis Aeterna and ended in ca. 111.M42, after the Primarch Roboute Guilliman successfully ended his Indomitus Crusade and brought Imperial reinforcements to defend Ultramar.
To the galactic north of Ultramar, the followers of the Chaos God Nurgle first established dominion in the Scourge Stars soon after the success of the 13th Black Crusade in precipitating the fall of Cadia. From this hive of corruption, armies of Nurglite daemons poured forth, accompanied by the traitorous Death Guard Legion along with Renegades and Chaos Cultists beyond count. Three loathsome spearheads pushed into Ultramar, attacking along a hundred fronts and bringing with them unnatural pestilence. The defenders of Ultramar -- Astartes and mortal alike -- fought bravely, but quickly lost ground. Ultramarine Primaris Space Marines of the Ultima Founding arrived not long after the successful completion of the resurrected Primarch Roboute Guilliman's Terran Crusade from Terra aboard Fleet Avenger to reinforce their brethren, but even these transhuman reinforcements could only slow the attackers' progress.
By ca. 111.M42, over a hundred standard years after the start of the Indomitus Crusade, the Imperial defenders all across Ultramar were depleted in dozens of ground campaigns, while a Plague Fleet systematically destroyed the realm's Ultramar Defence Fleet and star fortresses. Guilliman returned from the Indomitus Crusade after over a standard century of campaigning to stabilise the Imperium, and his deft and defensive manoeuvres bought time to launch what became known as the "Spear of Espandor" counterattack. The combined plague armies were eventually fought to a standstill amongst the ruins of Iax, before the Death Guard Daemon Primarch Mortarion escaped with his forces back to the Scourge Stars under cover of a Virus Bomb attack, both because of his brother's staunch defence and because Nurgle's realm in realspace had come under assault by the forces of the Blood God Khorne.
In a brief respite from the work of safeguarding the Emperor's realm after Mortarion's defeat, Guilliman ordered the rebuilding and decontamination of Ultramar, as well as the establishing of new procedures for creating further Ultramarines. It was not long before new Imperial Crusades called the Lord Commander of the Imperium away from Ultramar and back out into the dark galaxy. The Ultramarines then began the work of preparing their vengeance against the servants of the Dark Gods.
- Codex Adeptus Astartes - Space Marines (8th Edition), pp. 16-17
- Warhammer 40,000: Rulebook (8th Ediiton), pp. 40-47, 50-53, 123, 134, 152, 164-166
- Warhammer 40,000: Rulebook (6th Edition), pp. 168-177
- Warhammer 40,000: Rulebook (5th Edition), pp. 122-129
- Warhammer 40,000 Timeline