Horus Heresy - Timeline of Notable Events: Note: The following information was compiled by manifold and diverse hands at the order of Malcador the Sigillite and the Acting Council of Terra following the outbreak, as well as during, the major events of the Horus Heresy. As more information is uncovered in newly discovered Imperial records, it will be added to this chronology. Please see Great Crusade Chronology and Horus Heresy Chronology for a more complete record.992.M29 Ninth Battle of Xozer - In the Nordafrik Conclaves of Old Earth inexplicable ephemeral phenomenon are encountered during the battle where Kalagann, the techno-barbarian warlord of Ursh, is slain. The kingdom of Ursh is brought to heel by the Emperor's forces as the Unification Wars of Terra proceed.Unknown Date.M29 The Primarch Project - The Primarch Project, which was initially begun at some point in the late 29th Millennium by the scientists of the Imperial Biotechnical Division, far beneath the surface of Terra in the Emperor of Mankind's gene-labs, marked the Emperor's attempt to begin the creation of the next generation of Imperial super-soldiers to replace the Thunder Warriors. These were the primarchs, twenty extraordinary superhuman males who would be His generals -- great warriors, intellectuals and political leaders who would conquer thousands of worlds in His name.ca. 550.M30 The Primordial Strain - The Emperor begins His Space Marine project beneath the Himalazian (Himalaya) Mountains, creating the Primordial Strain of prototype Legionaries. These warriors are unstable and imperfect, but form the foundation for His future work building the Space Marine Legions.669.M30 Battle of Mount Arrarat - The last of the Thunder Warriors -- powerful but short-lived precursors to the Space Marines -- are wiped out in the final major conflict of the Unification Wars. While reports say they fell in valiant battle, rumours abound that the Emperor ordered them purged to make way for his nascent Legiones Astartes. One source claims that it is the nascent Ist Legion that is tasked with the elimination of the remaining Thunder Warriors alongside the Legio Custodes when the Thunder Warriors rebel against the Emperor soon after the first introduction of the Astartes. According to this tale, the Thunder Warriors realised after learning of the Space Marines' functional immortality that their inevitable decline into insanity and death was the result of the Emperor's imperfect augmentations of their bodies, and they felt betrayed by their creator.ca. 700.M30 The First Founding - Utilising the genetic material derived from the still-unborn primarchs, the Emperor, with the aid of the scientists of the Biotechnical Division and its director Amar Astarte, created the first gene-seed and implants it into His already elite Terran soldiers. These warriors provide the genesis of His Legiones Astartes. The 20 original Space Marine Legions are created during this so-called "First Founding." Grabiya's Theorem provides the solution to solve the diminishing stability of the Space Marines' gene-seed stores through over-use, due to the rapid expansion of the nascent Imperium of Man by the Legiones Astartes in this era. This theorem demonstrated that a primarch's genetic code could be used to stabilise and expand existing Astartes gene-seed stocks with what was hoped to be "minimal deviation" and mutation from the baseline genetic code. Sorian's Inductus Excelsus demonstrated that the need of the rapidly growing Imperium for more warriors was vast. Accelerated gene-culturing techniques were implemented, reducing the processing time to create a Space Marine from a mortal man to a single solar year. However, the gene-seed produced by these accelerated processes possessed unseen fundamental flaws.703.M30 First Pacification of Luna - This early Imperial campaign was the first operation mounted by elements of the early Space Marine Legions beyond the skies of Terra while the Terran Unification Wars were still raging across the surface of Mankind's birth world. The Imperium's first off-world target was Terra's own moon Luna -- domain of the Selenar gene-cults, whose technology is vital to expanding the numbers of the Legiones Astartes. The Selenar reject the diplomatic overtures of the burgeoning Imperium, and three nascent Space Marine Legions are unleashed to force Imperial Compliance. The combined force of the VII, XIII and XVI Legions (later named the Imperial Fists, Ultramarines and Luna Wolves, respectively) lifted from the surface of Terra in a scattering of rocket flame. The as yet unnamed XVI Legion had been chosen to serve as the Space Marine force's vanguard, and had brought its full strength to bear. In a daring surprise assault, the XVI Legion launched a planetary strike while their brother Legions drew fire from Luna's defensive weapons. Within six solar hours of the first shot being fired, Luna had been pacified and brought into Compliance, the first off-world conquest of the Imperium of Man. Faced with annihilation, the surviving Selenar cultists bent the knee to the Emperor instead, their surrender communique transmitted to Terra calling for the Emperor to "call off his wolves." The XVI Legion thus earned their name -- the Luna Wolves. During the conflict, the XVI Legion encountered evidence of occultism amongst the Selenar gene-wrights. The Selenar methodology is sequestered into the Imperial Dungeon beneath the Imperial Palace.712.M30 End of the Unification Wars - The Emperor consolidates His control over Terra and formally declares victory in the Unification Wars, bringing centuries of conflict to a close. Work intensifies on enforcing the rationalist state ideology of the Imperial Truth across the planet.739.M30 Treaty of Mars (Treaty of Olympus Mons) - Realising that war with the techno-cults of the ancient Mechanicum of Mars would be a long and costly affair, the Emperor instead brokers an alliance. In return for constructing a mighty war fleet and supplying weapons and machinery for his Legions, the Mechanicum are granted unparalleled autonomy as a client state of the Imperium, and continue to practice their faith in the Omnissiah as the Cult Mechanicus in violation of the Imperial Truth.ca.792.M30 The Scattered Primarchs - The Emperor's greatest work of gene-craft nears completion, combining advanced science with otherworldly secrets to create 20 superhuman children -- the perfect generals, pro-consuls and diplomats to lead his Legiones Astartes. These so-called primarchs are second only in power and skill to the Emperor Himself, but shortly before the Primarch Project's completion an unforeseen catastrosphe engineered through the machinations of the Ruinous Powers of Chaos scatters their containment tanks through the Warp to many different Human-settled worlds across the galaxy. But all was not lost, as the Emperor and his scientists still possessed their gene-sequences, which He had utilised as the genetic templates for the creation of His Legiones Astartes.798.M30 The Great Crusade Begins - With the furthest reaches of the Sol System firmly under Imperial control, the Emperor and his Space Marine Legions begin the Great Crusade. The first Mechanicum Explorator fleets leave the system to reclaim surrounding sectors of what will become the Segmentum Sol, carrying the hopes of Humanity with them.801.M30 Discovery of Horus Lupercal - The first of the lost primarchs is reunited with the Emperor, having spent his formative years engaged in vicious gang warfare on Cthonia, a nearby Mining World. Calling himself Horus, he pledges fealty to the Emperor and is given command of the XVI Legion, the Luna Wolves, spending many years as the Emperor's only returned son and one of His closest confidantes. Highly creditable claims state that the Emperor found Horus personally, the first of His lost sons, but no source specifies the location on Cthonia where the two met. Surrounded in millennia of myths and allegory, the truth of Horus' origins will more than likely never be known.803.M30 Liberation of Sol (Sedna Campaign) - During the Sedna Campaign, eight full Space Marine Legions are deployed to undertake the destruction of the artificial xenos nemesis world of Sedna on the outer edge of the Sol System, whereupon they expunge an alien faction bound to war by unknown psychic means. In the aftermath, the false world of Sedna falls into silence and is lost to Imperial auspices.819.M30 Discovery of Leman Russ - The Emperor travels to the frigid Death World of Fenris to meet Leman Russ, who challenges him to three contests: eating, drinking, and fighting. Although the primarch wins the first two, Leman Russ is humbled in the third and swears loyalty to the Emperor, who grants him command of the VI Legion -- soon to be known as the Space Wolves.821.M30 Discovery of [REDACTED] - Records expunged.824.M31 Discovery of Ferrus Manus - The Primarch Ferrus Manus spends his youth slaying machine-monsters and plundering the buried secrets of Medusa, his frozen homeworld. As overlord of Medusa's rival techno-clans, Ferrus joins the Great Crusade after a cataclysmic meeting with the Emperor -- taking command of the X Legion, which he renames the Iron Hands.830.M31 Discovery of Fulgrim - The Emperor came to the industrial Mining World of Chemos and was reunited with His lost son Fulgrim, who had rebuilt his ravaged and resource-poor homeworld. Upon their first meeting, Fulgrim recognised the Emperor for who He truly was. Fulgrim bent his knee and offered his sword in eternal servitude. Pleased, the Emperor brought Fulgrim into the Imperial fold, and not long after, gave him command of the III Legion. The first speech Fulgrim gave to the III Legion moves the Emperor to rename them the Emperor's Children -- an extraodinary honour that Fulgrim swears to uphold by striving for perfection in all things.832.M30 Discovery of Vulkan - The Primarch Vulkan was raised by a blacksmith on the fiery, volcanic world of Nocturne, becoming a giant hero amongst his people. The Emperor arrived upon Nocturne and reunited with His lost son, who only agreed to serve the Emperor after competing in a difficult challenge to slay the largest salamander -- a large drake-like creature native to Nocturne. During the contest, Vulkan's life ended up in jeopardy, and though the Emperor had obtained a larger prize, He sacrificed His trophy in order to save His gene-son's life. Humbled by the stranger's deed of self-sacrifice, Vulkan bent his knee to the Master of Mankind. It is believed he served with the Emperor for some time before he finally took command of the XVIII Legion -- the Salamanders.835.M30 Discovery of Rogal Dorn - The Great Crusade reaches the Inwit Cluster, a collection of Ice Worlds ruled by the Primarch Rogal Dorn. The lost primarch, the seventh to be rediscovered, greets the Emperor on the bridge of the Phalanx, a colossal reactivated starship dating back to the time of the Age of Technology, and submits to his authority. The Emperor quickly instructs Dorn in the ways of the Imperium and their objectives with the Great Crusade, and soon passes off command of the VII Legion, whom Dorn remakes into the Imperial Fists. The primarch transfers their headquarters to the Phalanx.837.M30 Discovery of Roboute Guilliman - Raised on the world of Macragge by a noble consul, the Primarch Roboute Guilliman grows into a prodigal leader. The Emperor's arrival is delayed for years by Warp Storms -- by the time He arrives, the primarch rules a stellar empire known as the Realm of Ultramar, the "Five Hundred Worlds." Impressed with His son's superlative organisational skills and strategic planning, the Emperor quickly passes on command of the XIII Legion to Guilliman, who reforges them into his own, as the newly renamed Ultramarines.ca. 839.M30 - ca. 890.M30 Rangdan Xenocides - The Titans of the Legio Gryphonicus as well as the Legio Vulturum, the Legio Kydianos and other Xanithe Mechanicum forces from Xana II served alongside the vaunted Dark Angels Legion during the vital campaign known as the Rangdan Xenocides. The Dark Angels hurled themselves at the enemies and broke their greater strength in countless battles against the xenos on the edge of the Halo Stars. This campaign culminated in the Third Rangdan Xenocide around 890.M30, which resulted in the loss of the lives of 50,000 Space Marines spent in preventing the destruction of perhaps the entire northern Imperium by the alien menace from the outer darkness. Due to the extensive losses suffered by the I Legion, by 899.M30, the Ultramarines Legion was on the cusp of becoming the largest of the Legiones Astartes, standing at around 166,000 Legionaries.840.M31 Discovery of Magnus the Red - A strong Warp presence is detected on the remote world of Prospero, leading the Emperor to investigate. There He finds Magnus the Red, the most psychically gifted of his sons, and embraces him as commander of the XV Legion, the Thousand Sons. Magnus learns much from the Emperor's psychic might in the following years.843.M30 Discovery of Sanguinius - Borne by the currents of the Warp to a moon scorched by radiation from an ancient thermonuclear war, Sanguinius possesses magnificent, angelic wings and psychic foresight. He thus foresees the arrival of the Emperor, and pledges himself to the Imperium in exchange for the safety of Baal's rad-scarred and pious people. Not long after their reunion, Sanguinius is given command of the IX Legion and remakes them in his own image, renaming them the Blood Angels.846.M30 Discovery of Lion El'Jonson - Forward scouts of the Great Crussade encounter the Death World of Caliban, and the knightly orders that protect it from Warp-spawned beasts. Their leader, Lion El'Jonson, is found to be one of the lost primarchs, and assumes command of the I Legion upon meeting the Emperor -- later renaming them the Dark Angels after an alleogircal figure of Calibanite myth from his youth. A young, newly-inducted Calibanite I Legion Librarian, Zahariel El'Zurias narrowly averts an attempted assassination on the Emperor's life soon after His arrival.849.M30 Discovery of Perturabo - A scientific and military genius on the world of Olympia draws the Emperor's attention, found to be his lost son, the Primarch Perturabo. The bitter and analytical primarch judges the IV Legion's war record to that point in the Great Crusade harshly, and orders their decimation -- execution of one in every ten Legionaries -- as punishment. Drawing lots, one in nine IV Legion Astartes are killed by their remaining battle-brothers with their bare hands. Following this action, Perturabo leads his Legion to the Meratara Cluster and forges them into a Legion in his own image. The IV Legion formally becomes known as the Iron Warriors.854.M30 Discovery of Mortarion - The Primarch Mortarion rebelled against the sorcerous xenos overlords of the toxic Death World of Barbarus, building an army from the suffering people of that poisonous planet. The Emperor comes to Barbarus in his Principia Imperialis fleet and reunites with His lost son Mortarion. Upon meeting the Emperor for the first time, Mortarion was oblivious to any obvious connection or physical resemblance. Angry, Mortarion declared that he and his Death Guard needed no help to finish their quest for justice. The Emperor quietly challenged the stormy young primarch's assertion, pointing out his soldiers' failure to reach the last high citadel of the High Overlord Necare, and then threw down a gauntlet. If Mortarion could defeat the high overlord alone, he would withdraw and leave Barbarus to its own means. But if he failed, the primarch would join His Imperium of Man and Mortarion would swear total fealty and allegiance to the Emperor. Mortarion was true to his oath, and when he failed to overwhelm the last of Barbarus' sorcerous overlords without the intervention of the Emperor, he bent his knee to the stranger and swore himself and the Death Guard to His service. Only then did the Emperor reveal Himself as the young primarch's true father, and the destiny such service would bring: command of the XIV Legion. Shortly thereafter, the Emperor gave his son command of the Dusk Raiders. Mortarion remade them in his own image, renaming them the Death Guard. However, Mortarion never forgave the Emperor for supposedly denying him his vengeance -- and his chance to prove that he was truly better than his foster father Necare.857.M30 Discovery of Lorgar Aurelian - Lorgar Aurelian, archpriest of the theocratic Covenant of Colchis, met the arrival of the Emperor with great ceremony, believing him to be the saviour and long-awaited god of the Colchisian faith that he had spread across that world. Despite his insistence to the contrary to his father, the primarch preaches the Emperor's divinity across the galaxy at the head of the XVII Legion. He reshapes the XVII Legion, once called the Imperial Heralds, in his image, and renames them the Word Bearers. Lorgar at this time is considered one of the weaker primarchs by his brothers, largely because of his odd devotion to religion, something specifically prohibited by the atheistic Imperial Truth.865.M30 Discovery of Jaghatai Khan - After conquering the Feral World of Chogoris with a great nomadic army of steppe horsemen, Primarch Jaghatai Khan encounters the Emperor arriving with the Great Crusade's Principia Imperialis Expeditionary Fleet. Faced with submission or subjugation, the Great Khan pledges his sword to the Imperium and claims command of the V Legion -- his White Scars.896.M30 Discovery of Konrad Curze - Stranded on the sunless world of Nostramo and plagued by precognitive visions, Primarch Konrad Curze becomes known as the "Night Haunter" for his brutal enforcement of justice. When the Emperor finally arrives, alongside several of His primarch sons, including Magnus the Red, Rogal Dorn and Fulgrim, as well as representatives from the Ultramarines Legion, Curze experiences a vision so terrible he tries to claw his eyes out -- nevertheless, he is placed in command of the VIII Legion -- which he reshapes into the fearsome Night Lords, who specialise in the use of terror as a weapon.899.M30 Discovery of Angron - The Emperor arrived at the world of Nuceria, where he observed his long-lost son, the Primarch Angron Thal'kyr, lead a revolt of slave-gladiators against their cruel overlords. Angron had been found after his arrival on Nuceria as a young adolescent and sold into slavery. He then underwent horrific surgery, where barbaric cybernetic cranial implants known as the Butcher's Nails were inserted into his brain to increase his aggression. Thrown into the fighting pits for his masters' pleasure, he soon rose to the top, and became the "Lord of the Red Sands." On the eve of the largest gladiator exhibition ever held by the slave masters of the city of De'shea, Angron led a successful slave revolt and escape by many of his fellow gladiators. Taking refuge within the De'shea Mountains, the night before their final confrontation with their cruel overlords, Angron dug his own grave, ready to die alongside his brothers and sisters in the name of freedom. But before the battle took place, the Emperor intervened and teleported Angron aboard His own flagship, unwilling to see one of his primarchs slain before he could be put to use in the Great Crusade. Angron's fellow gladiators were slain to the last man and woman. Angron is enraged that he was denied an honourable death alongside his beloved comrades, and swears never to forgive the Emperor. Angron was then examined on Terra and given over to his genetic sons from the XII Legion, the War Hounds. After assuming command, he reshaped his Legion in his own savage image, and they became the World Eaters.922.M30 Discovery of Corvus Corax - Raised by prisoners on the mine-moon Lycaeus, Primarch Corvus Corax leads a revolution and renames his home Deliverance. When the Emperor arrives in the Principia Imperialis fleet, the two hold a secret conversation which lasts a solar day and a night -- after which Corax is left to subjugate the world of Kiavahr alone, and ultimately agrees to lead the XIX Legion. Corax quickly transformed his Legion in his own image and renamed them the Raven Guard.927.M30 Discovery of [REDCATED] - Records expunged.964.M30 Razing of Monarchia - Monarchia was the name of the capital city of the planet Khur, built as a beautiful shrine to the God-Emperor by the XVIIth Legion, the Word Bearers Space Marine Legion during the Great Crusade. Monarchia, along with its false temples, was destroyed by the warriors of the Ultramarines Legion as an object lesson in the folly of false religion. The entirety of the XVIIth Legion was then forced to kneel in the ashes of their devotion by the Emperor Himself, while the Ultramarines stood over them in judgement -- that which they had seen as worthy devotion now labelled treasonous. Suffering such a humiliating rebuke at the hands of the Ultramarines, this insult would apparently fester within the XVIIth Legion and drive them willingly into heresy.965.M30 <ALL DATA REDACTED>966.M30 Cadia Discovered - The world of Cadia is entered into the Carta Imperialis during the Pilgrimage of Lorgar.969.M30 <ALL DATA REDACTED>972.M30 Farinatus Extermination - This campaign is carried out by the Night Lords and the Raven Guard Legions.981.M30 Discovery of Alpharius Omegon - Conflicting reports surround the return of the Primarch Alpharius to the XX Legion. Some claim he was found leading a renegade fleet by Horus himself, or saved by the Emperor from the alien Slaugth. Others suggest he was marooned upon a Dead World -- or was never lost at all, but raised on Terra itself. Of the complete truth, none can tell. One extant account states that Alpharius was discovered accidentally by the Luna Wolves when they were lured into a trap after receiving a distress beacon from one of their own battleships. When they went to assist, Horus's flagship Vengeful Spirit came under attack by an unknown enemy, and a single assassin broke into the flagship and fought his way clear to Horus' command chamber. Horus himself was forced to confront him, but thankfully, did not slay his attacker but recognised him instead as his lost brother primarch -- Alpharius. Unfortunately, the validity of this account is considered highly suspect, as is so much else about the Alpha Legion and its primarchs.981.M30 Alpharius assumes command of the XX Legion - <RECORDS NOT AVAILABLE>984.M30 Destruction of Nostramo - The destruction of Nostramo was an Exterminatus action conducted by the now-rogue Night Lords Legion after the Night Haunter's attack on Rogal Dorn towards the end of the Great Crusade, after the pacification of Cheraut. The VIIIth Legion willingly destroyed their own homeworld of Nostramo on the order of their Primarch, concentrating deadly lance-strikes on the planet's unstable core which resulted in tumultuous seismic activity that eventually shattered the dark planet apart in a wave of destruction. This event fulfilled the Night Haunter's vision of seeing his planet being destroyed by beams of white light that erupted from the heavens. For this crime, Curze was recalled to Terra by the Emperor to be reprimanded for his brutal tactics, but instead he joined the Warmaster Horus in open rebellion during the Horus Heresy before he could stand before his father.994.M30 Isstvan System First Brought to Imperial Compliance - The Raven Guard Legion completes the initial Imperial conquest of the Isstvan System. Vardus Praal is left to serve as planetary governor of Isstvan III, the most heavily populated world in the system.000.M30 Triumph of Ullanor - The Emperor declares the Great Crusade won in the wake of its greatest victory over the Orks in the Ullanor Crusade and returns to Terra to begin His "Great Work," pronouncing His favoured son, Horus, to be the new Imperial Warmaster to carry out the final battles of Imperial Compliance and extermination in His name across the remaining dark frontiers of the galaxy. The Space Marine Legions present at the triumph include: the Alpha Legion, Blood Angels, Death Guard, Emperor's Children, Imperial Fists, Luna Wolves, Thousand Sons, Ultramarines, White Scars, Word Bearers, and World Eaters.000.M30-007.M31 Chondax Campaign - Shortly after the Triumph of Ullanor, Jaghatai Khan and his V Legion were next sent to the worlds of the Chondax System. The system was comprised of the planets Epihelikon, Teras, Honderal, Laerteax and Phemus IV, the furthest of the outlying worlds. The culmination of this campaign took place upon the world of Chondax, labeled Chondax Primus EX5, 776 NC-X-S by Imperial cartographers, but named "The White World" by the White Scars due to its salt-like earth. The White World was the crucible of the whole campaign, the heart of those Greenskin forces that had chosen to go to ground in the system. The Khan was ordered by the newly-promoted Warmaster Horus to hunt the remnants of the Ork empire destroyed on Ullanor, the last slivers of the Warlord Urlakk Urruk's Greenskins. The brutal campaign lasted six long standard years as the White Scars hunted the remaining Greenskin forces to extinction. It was at Chondax that the White Scars would first learn of the outbreak of the Horus Heresy and the betrayal of Horus Lupercal. Delayed by the arrival of the fleet of the Alpha Legion, the White Scars would break-out from the Traitors' cordon and begin the long journey back to Terra in search of answers -- leaving multiple Alpha Legion warships as flaming wreckage in the bargain.001.M31 Council of Nikaea - There was an increasing concern as the Great Crusade progressed about the use of psychic abilities. More and more often during the progress of the Imperial conquest of the galaxy, the Imperial Army and Space Marines would make planetfall only to find that the populace was in thrall to mysterious powers and unnatural mystics and so-called "sorcerers." These powers were also very akin to those used by the Thousand Sons Legion of the Primarch Magnus the Red. His psychically potent Thousand Sons Legion had come under criticism for their use of sorcery by some of their fellow Legiones Astartes. The schism grew so great that it threatened the very stability of the fledgling Imperium and so the Emperor Himself had called for an Imperial conclave after solar decades of controversy to resolve the issue of the use of psychic powers in the Imperium once and for all. This conclave was held upon the world of Nikaea, which was intended to determine whether or not the use of psychic sorcery represented a boon or a grave danger to Mankind and the newborn Imperium of Man. The Council of Nikaea was also the trial of Magnus the Red, for he was accused of sorcery and of introducing sorcerous practices to the Space Marine Legions through the institution of the corps of Librarians which had been done at his initiative. Ultimately the existence of psykers in the Imperium, such as astropaths and Navigators, was allowed but tightly restricted under centralised Imperial control, while the potent and unrestricted use of psychic abilities that was defined as sorcery was officially banned, as was the Librarius divisions of all the Space Marine Legions. The Librarians were ordered under the Edicts of Nikaea to never again make use of their abilities and return to their roles as ordinary line Astartes. The Chaplain Edict, modelled on the practices of Lorgar and the Word Bearers Legion, established a corps of Chaplains in every Legion whose role was to bolster the morale of their battle-brothers and ensure that all Imperial rules and dictums were obeyed. The psychically powerful Maganus and his Thousand Sons would continue to study such forbidden powers in secret on their homeworld of Prospero, which would ultimately lead them into damnation by the Ruinous Powers during the early days of the Horus Heresy.002.M31 Kayvas Belt Expedition - Many tribes of Orks, scattered and leaderless after the hammerblow they had suffered at Ullanor during the Ullanor Crusade, had fled to the points of the etheric compass – and many had come to rest in the Kayvas Belt, where they carved new outposts out of the drifting, mineral-rich rocks, licked their wounds while they re-armed. The Alpha Legion had tracked them to their lair and petitioned the Warmaster Horus for the reinforcements required to prosecute their plan of annihilation, but after the war at the world called Murder and the disastrous engagement with the civilisation known as the Interex, the Luna Wolves had been reluctant to commit ships to Alpharius’ new campaign. In the end, it was the Blood Angels who agreed to assist their cousins in the XXth Legion, with Sanguinius himself marshalling a sizable intervention to support the efforts of the 88th Expeditionary Fleet. The mission, Alpharius said, would be five standard years in execution. The Angel rejected that premise and promised it would be over in one, and he committed vessels from every active Blood Angels expeditionary fleet to the cause. Sanguinius was proved right -- more or less. Just over thirteen months after the commencement of the Kayvas initiative, the Orks were almost totally annihilated.003.M31 Contact lost with Isstvan System003.M31 Luna Wolves renamed the Sons of Horus004.M31 Davin Campaign and the Fall of Horus - The Warmaster Horus is grievously wounded while fighting rebels on the moon of the Feral World of Davin. He is healed within the ancient Temple of the Serpent Lodge on the surface of Davin but though his life is saved, his soul is forfeit to the Ruinous Powers. The Chaos Gods, acting in rare concert, exploited Horus' psychological weaknesses -- his need for power and recognition and his jealousy and hurt over his fear of losing his place as the Emperor's most favoured son after the Emperor "abandoned" him to return to Terra -- to turn him against his father. From this day forwards Horus makes his plans to bring the Imperium to ruin and topple the Emperor from power. Though his treachery and malign intent remain hidden, he begins his far-reaching conspiracy to suborn those of his brothers' Legions and the other forces of the Imperium who will aid him and neutralise the threat of those who will not where he can, while preparing in secret to fight a sudden and ruthless civil war.004-006.M31 Signus Cluster Campaign - The bulk of the Blood Angels Legion is dispatched to the distant Signus Cluster to put down a local uprising. Knowing the IX Legion will never join his cause and fearing their Primarch Sanguinius, Horus sets his trap at Signus Prime, where the Blood Angels are beset by a foe none have ever faced before, the Daemon legions of the Ruinous Powers, and assailed by terrifying psychic assaults and distortions of reality. There, the Blood Angels discover worlds scoured of life -- trapped on Signus Prime, they are ambushed by a horde of Daemons, facing horrific casualties until their primarch defeats the murderous Bloodthirster Ka'bandha in single combat.004.M31 Destruction of Olympia - While the Iron Warriors Legion were cleansing the world of Gugann of a major infiltration of the infamous xenoform known as the Hrud, the long-lived Satrap of Olympia died. With the death of the Tyrant of Lochos, the Iron Warriors' homeworld erupted into infighting and insurrection. The population had taken up arms against the Imperium following years of relentless anti-Imperial propaganda by the dead Tyrant. Tired of repeatedly having to prove himself, and enraged at the disregard his fellow Legiones Astartes, the Primarch Perturabo and the Iron Warriors brutally suppressed the rebellion on the streets of the city-states of Olympia. No one was spared. It was the principle of surrender or no quarter, and the Iron Warriors had grown accustomed to granting no quarter. Perturabo watched as the Olympian fortifications in which he had once taken such pride were overcome. By the time the massacre was over, Olympia had been culled into slavery. Five million civilians had been killed in the process.004-005.M31 Start of the War in the Webway - Learning of Horus' treachery and agreement with the Chaos Gods to initiate a rebellion against the Emperor through the use of forbidden sorcery, Magnus the Red attempts to warn the Emperor on Terra via psychic projection. In the process, he breaches the wards around the Great Work -- a conduit built by the Emperor and the adepts of the Mechanicum from the dungeons of the Imperial Palace into an extradimensional xenos network once governed by the Aeldari called the Webway. The Daemons of Chaos flood into the Imperial extension into the Webway from the Warp, forcing the Legio Custodes and Sisters of Silence into a solar-decade-long war to protect the heart of Terra itself.004-014.M31 Burning of Prospero (First Battle of Prospero) - Magnus, primarch of the Thousand Sons, learns of his brother Horus' fall to Chaos and attempts to warn the Emperor using psychic arts forbidden by the Edicts of Nikaea. He inadvertently unmakes his father's Great Work in the Webway and the Space Wolves, accompanied by elements of the Legio Custodes and the Sisters of Silence as part of a Retribution Fleet, are ordered to bring him to Terra to answer to his father for this crime. The Warmaster Horus intervenes and convinces his brother Leman Russ, primarch of the Space Wolves, that Magnus' crime is so dire that his life must be forfeit. The Space Wolves raze Prospero and its capital city of Tizca to ashes, and while Magnus and his Space Marines escape through a Warp rift opened by the Chaos God Tzeentch deep into the Immaterium, his Legion is reduced to but a thousand warriors.005-014.M31 Schism of Mars (Martian Civil War) - Fabricator-General of the Mechanicum Kelbor-Hal turns against the Imperium and plunges Mars into civil war, those loyal to Terra and the Emperor as the Omnissiah are forced to abandon the Red Planet. Led by the Legio Mortis ("Death's Heads"), the Traitor Mechanicum scoured the surface of the Red Planet of those still loyal to Terra, plunging the first and most important Forge World of Mankind into a bitter civil war that saw the extinction of several ancient Collegia Titanica Legios and dozens of Knight houses. The last to fall were the Loyalist hold-outs of the Legio Tempestus ("Stormlords"), who, perhaps mercifully, died unaware that the bulk of their Legio off-planet had renounced their oaths to the Emperor and declared for the Warmaster Horus. Elsewhere, the Schism of Mars sunders the feudal order of the ancient Mechanicum and its bonds with the Imperium. Many Forge Worlds side with the Traitors, others with the Emperor and still others declare independence from either side. So likewise are the Mechanicum's Titan Legions, the Skitarii Legions and the powerful Forge World Taghmata riven with division. Neither side is able to claim victory for the duration of the Horus Heresy, and Imperial Fists saboteurs fight to disrupt the Traitors' industrial capabilities until the final days of the war. The Traitors of the Mechanicum are soon known as the "Dark Mechanicum."005-006.M31 Isstvan III Atrocity - The Warmaster Horus mustered four entire Legiones Astartes to put down a rebellion against Imperial rule at Isstvan III, and having turned the primarchs of those Legions to his treacherous cause, engineered the purging of tens of thousands of Legionaries not trusted to follow them into treason because of their continued loyalty to Terra and the Emperor. The ancient magicks of the Isstvanian Sirenhold are unleashed against the forces of the Sons of Horus, Emperor's Children, Death Guard and World Eaters. The battle against the rebel planetary governor Vardus Praal and his Slaaneshi Warsingers is won, but is ultimately in vain when the four Legions unleash a terrible virus bombing of Isstvan III while the Loyalist Astartes are engaged against the rebels. All does not go to plan, however, and many of the Loyalists survive to force Horus to engage them in a vicious battle lasting for several solar months among the ruins of the planet's capital, the Choral City, before they are finally wiped out by orbital bombardments when the obstructive planet-wide clouds unleashed by the virus-bombing clear. At the same time, a small number of these Loyalists escape the carnage to carry word of the Traitors' actions to Terra aboard the frigate Eisenstein. This action marks the formal start of the great interstellar civil conflict that will later be named the Horus Heresy.006-007.M31 - Chondax Campaign - Waylaid fighting Orks on the galactic fringe for five standard years, the White Scars discover the hand of the Alpha Legion behind their misfortunes. The Alpha Legion, supposedly driven by the commands of both the Warmaster Horus and the xenos organisation known as the Cabal, openly engaged the White Scars in the Chondax System after standard years of shadowed ambushes. Their exact purpose is unclear it would seem, even to the XXth Legion itself. For unknown reasons, the Alpha Legion cease their blockade -- allowing the White Scars' Primarch Jaghatai Khan to receive word of the Warmaster Horus' betrayal of the Emperor when in the wake of the engagement, they established contact with the Primarch Leman Russ on Terra in the aftermath of the Space Wolves' destruction of Prospero. Faced with the dilemma of aiding the weakened Space Wolves against a powerful force of Alpha Legion attackers, or returning to Terra as ordered by Rogal Dorn, their Jaghatai Khan chooses a third option. Seeking out answers for himself as to who is truly loyal to the Emperor and who is not, he orders his fleet to set course for Prospero to ascertain what has truly occurred there.006-014.M31 Imperial Fists' Blockade of Cthonia - The Imperial Fists blockade Cthonia, homeworld to the Sons of Horus, but the Traitors are too heavily entrenched to be removed. The VII Legion maintain their occupation for standard years, preventing all attempts to break free, until a Sons of Horus strike force arrives to break the siege and turn the tables on the sons of Rogal Dorn.566.006.M31 Drop Site Massacre of Isstvan V - With Terra warned of the Warmaster Horus' treachery at Isstvan III, eight entire Space Marine Legions, half of the known forces of the Legiones Astartes, are ordered by Terra to crush the Traitors' rebellion at Isstvan V, but unbeknownst to the rest, Horus has already turned three of these Legions to his service and ensured the fourth is delayed. The first wave of Loyalist Legions -- the Iron Hands, Raven Guard and Salamanders -- makes planetfall but is betrayed by the second wave coming behind them -- the Alpha Legion, Night Lords, Iron Warriors and elements of the Word Bearers -- in the bloodiest three solar hours of war ever fought by the Legiones Astartes. In the aftermath of the great betrayal, three Legions are almost entirely wiped out, one primarch, Ferrus Manus, is slain in the battle by Fulgrim and two others -- Vulkan and Corvus Corax -- are missing in action, though in fact Coraxmanaed to escape off-world with the remnants of his Legion. The survivors of the Iron Hands, Raven Guard and Salamanders who manage to escape off-world or remained elsewhere in the galaxy become known as the "Shattered Legions."006-011.M31 Succession Wars - A vital space lane is seized by the Alpha Legion, who through sheer misfortune cross paths with a Loyalist company of Iron Warriors, forcing an unexpected and bloody struggle. The region changes hands many times over the course of the next five Terran years, leaving the core world of Paramar V little more than a devastated husk.006.M31 First Battle of Paramar - Alpha Legion forces allied with the Traitor Dark Mechanicum of Taghmata Satarael and the Titans of the Legio Fureans mount a surprise attack on the strategically vital lynchpin system of Paramar before their true allegiance becomes known to the defenders. Paramar is a vast arms cache of the Great Crusade and a vital communications hub. The Pharaeon of Paramar, its primary void station, is quickly taken, but a full planetary assault of Paramar V becomes necessary as Loyalist Mechanicum and Legio Gryphonicus Titan forces, as well as the unexpected intervention of a Loyalist cadre of the Iron Warriors Legion, offers the invaders strong resistance. The valiant defence however is overwhelmed and Paramar falls to the Traitors, cutting off much of the most stable transit routes to the northern Imperium.006.M31 <ALL DATA REDACTED>006.M31 Sundering of Zhao-Arkad007.M31 Battle of the Alaxxes Nebula - As the Space Wolves are still licking their wounds following their heavy losses during the Razing of Prospero, they are ambushed by a sizable Alpha Legion strike force and are subsequently routed at Yarant. Primarch Leman Russ organises a tactical retreat and flees towards the Alaxxes Nebula. The Alpha Legion gives chase and soon the VIth Legion finds themselves in a precarious predicament -- they are effectively cut-off and surrounded. Though Russ reluctantly sends an distress call for assistance to his brother-Primarch Jaghatai Khan, of the White Scars Legion. The Khan declines to assist the Space Wolves and instead sets course for Prospero to determine the truth for himself in regards to the Warmaster's heresy. The Space Wolves are eventually forced to flee in order to survive. A final confrontation eventually erupts between the Loyalist and Traitor forces as the Space Wolves vow to take as many of their foes with them before they are annihilated. The Sons of Russ receive relief from an unexpected quarter, in the form of the Dark Angels Legion, and their mighty Star Fort, the Chimaera. Answering Russ' distress signal, the combined force of Loyalists are able to turn the tide, and inflict serious losses on the Alpha Legion, and force them to withdraw.007.M31 Battle of Phall - Having been cast off-course and stymied by Warp Storms en route to Isstvan V by the machinations of the Warmaster Horus' dark allies in the Empyrean, the Imperial Fists' Retribution Fleet is becalmed for long solar months at the Phall System. Only by maintaining a constant state of readiness and the genius of their commander is the fleet saved from utter destruction when the Traitor Iron Warriors attack their hated rivals. Dozens of capital ships are lost as boarding actions take place on both sides. The Imperial Fists board Perturabo's flagship and almost secure victory. But at the height of the engagement, an astrotelepathic message from Terra finally breaks through the turbulent Warp, as Rogal Dorn, the primarch of the Imperial Fists, orders his fleet to return to the Throneworld at once.007-009.M31 Shadow Crusade - The Word Bearers and World Eaters invade the Five Hundred Worlds of Ultramar with the aim of utterly destroying the domain of the Ultramarines and drawing Loyalist forces away from the Warmaster's advance on Terra. During the conflict, which centres around the perfidious attack of the Word Bearers at the Calth Muster, scores of worlds are ravaged and the involvement of the Ruinous Powers in aid of the Traitor cause is first widely manifest in open war, transfiguring both of the Traitor Legions involved.007-009.M31 Manachean War and the Dark Compliances  - His treachery revealed at last, the Warmaster begins his relentless advance on Terra, forcing his Dark Compliance of countless regions across the northern Imperium to provide his forces with a resource base to fight what will now become a protracted and relentless war. Foremost among his targets are the Manachean Commonwealth, the Coronid Deeps and their surrounding regions, where a particularly savage campaign is conducted by the Sons of Horus and Death Guard which brings the economically vital worlds of the Manachean Commonwealth to fuel the Traitors' cause. This wider campaign also places the fleet anchorage of Port Maw under the Warmaster's talon and sees the stubbornly Loyalist Forge Worlds of Lucius and Mezoa isolated and besieged, while the Traitor-aligned Forge World of Cyclothrathe begins to carve out its own pocket empire in the region.007.M31 The Calth Conjunction, Battle of Calth and the Birth of the Ruinstorm - Mustering at the world of Calth in the Realm of Ultramar on orders issued by the Warmaster Horus before the Isstvan III Atrocity, the Ultramarines and Word Bearers prepared for a campaign against the Orks of the Ghaslakh xeno-hold. The Ultramarines were unaware of the Word Bearers' true allegiance and utterly unprepared for betrayal, and suffered horrific losses as a result. The Traitors' real objective was to incur enough casualties on the world after murdering Calth's Veridia star as a sacrificial offering to the Ruinous Powers that would bring about the birth of the Ruinstorm, a Warp Storm so large it would sever the galaxy in half and render all long-range Warp travel unpredictably dangerous, and trans-luminal astrotelepathic communication all but impossible. The death of the system's star bathes Calth's once-vibrant biosphere in deadly radiation. This action paved the way for Horus' rapid advance on Terra. The so-called "Age of Darkness" begins.007-017.M31 The Underworld War on Calth - Following the events of the Battle of Calth, the Word Bearers performed one last act of spite and caused the planet's primary star to become unstable. The surface of Calth was ravaged by the radiation emitted by the slow death of the Veridia star. The continuing Battle of Calth between trapped forces of those Ultramarines and Word Bearers still locked in a death-struggle descended into the extensive arcologies deep beneath the planet's surface. This so-called "Underworld War" ground on for ten solar years before the last of the Traitors was finally hunted down and slain, a period that extends beyond even the end of the Heresy itself.007-008.M31 Shadow Crusade - The Word Bearers and World Eaters, led by the Primarchs Lorgar and Angron, invade the Five Hundred Worlds of the Realm of Ultramar with the aim of utterly destroying the domain of the Ultramarines Legion and drawing Loyalist forces away from the Warmaster Horus' advance on Terra. The Traitors burn every world their fleet encounters. During the conflict, which occurrs concurrently with the perfidious attack of the Word Bearers at the Calth Muster during the Battle of Calth, scores of worlds are ravaged and the involvement of the Ruinous Powers in aid of the Traitor cause is first widely manifested in open war, transfiguring both of the Traitor Legions involved. Roboute Guilliman confronts his brothers at Nuceria, Angron's hated homeworld, and halts their rampage, but not before dark powers possess Angron and transform him into a daemonic avatar of bloodshed, a Daemon Prince of Khorne.The Ruinstorm (007-011.M31) - Fuelled by the sorcerous rituals of the Word Bearers and the carnage unleashed by the Battle of Calth and the Shadow Crusade in Ultramar, a vast Warp phenomenon dubbed the "Ruinstorm" inhibits travel and communication across Imperial space, cutting whole regions of the galaxy off from the Astronomican's guiding light. While the Warp-touched Traitors can navigate freely, three Loyalist Space Marine Legions -- the Dark Angels, Blood Angels and Ultramarines -- are stranded far from Terra, unable to assist in its defence.007-015.M31 Solar War - The battle for the Sol System, known as the Solar War and long-threatened, begins as Traitor infiltration forces and probing raids from without, and Dark Mechanicum attacks and attempted break-outs from besieged Traitor-controlled Mars test the defences of the Throneworld of Humanity. Traitor ships assault the Segmentum Solar under the cover of refugee flotillas, bringing the war to Terra's doorstep. The Alpha Legion comes within striking distance of the Throneworld in the Battle of Pluto, only for Alpharius to meet his death at the hands of Rogal Dorn. Despite this, the Alpha Legion's command structure appears as strong as ever. Conflict within the system is not concluded until the eventual lifting of the Siege of Terra in 014.M31 and the cleansing of remaining Heretic forces from Mars in 015.M31. {See Extrapolation Addenda CVX-CVXVIII-Classified Amaranth-Gold}007.M31 The Wolf and the Khan - The White Scars learn of the Warmaster's heresy when they establish contact with Leman Russ in the aftermath of the Space Wolves' destruction of Prospero. Faced with the dilemma of aiding the weakened Space Wolves against a powerful force of Alpha Legion attackers, or returning to Terra as ordered by Rogal Dorn, Jaghatai Khan chooses the higher duty and returns to Terra.007-010.M31 Thramas Crusade - Horus ordered the Traitor Primarch Konrad Curze of the Night Lords to neutralise the three Forge Worlds of Thramas, thereby denying the Loyalists a major source of war machines and materiel in the eastern Imperium. They succeeded in destroying two of the region's Forge Worlds and damaging the third grievously. The Dark Angels then responded to reports of atrocities committed across the Eastern Fringe, revealed to be the work of the Night Lords. The vengeful conflict that follows lays waste to hundreds of Imperial territories, but ends with Konrad Curze and many of his senior commanders presumed dead or captured by Lion El'Jonson, while the Night Lords Legion scatters into dozens of independent warbands.007-008.M31 Siege of the Perfect Fortress - Located on the world of Narsis, the so-called "Perfect Fortress" had been erected by the IIIrd Legion, the Emperor's Children, during the Great Crusade,designed by the Primarch Fulgrim and his brother Perturabo, a genius at siege tactics. Following the XIXth Legion's catastrophic losses and the ill-fated attempt to quickly replace these losses, Corvus Corax decided that his Legion would assail the highly symbolic location to prove that it was still a formidable fighting force. Through the use of Corax's superlative military tactics and stratagems, the so-called "Perfect Fortress" fell within the solar day. The strategem used was for the impregnable fortress to come under futile attack by an Imperial Army cohort, who are run down and butchered by the Emperor's Children. The defenders return to find their vacated fortress occupied by the Raven Guard, who swiftly turn the powerful defensive weapons on their arrogant former brothers. This highly symbolic action not only marked a severe defeat for the increasingly notorious Traitor Marines of the IIIrd Legion, but also the return of the XIXth Legion to the front lines during the Heresy. It was purely an act of spite against Horus, and even though its choice to serve the Emperor nearly brought it to extinction, the Raven Guard still opposed him and proved to be a thorn in the Archtraitor's side.008-013.M31 Siege of Baal - Baal, homeworld of the Blood Angels, becomes a sanctuary for Space Marines fleeing Horus' rebellion. Fearing the Shattered Legions will reorganise and pose a threat to his plans, the Warmaster besieges the planet, although every attempt to conquer Baal is rebuffed with a heavy toll of casualties.008-009.M31 Vannaheim Space Drop - The Iron Warriors launch a daring void assault against the orbital hives of the world of Vannaheim, capturing vital facilities after ten solar days of brutal fighting. A Loyalist force in the Segmentum Tempestus, including isolated elements of the Space Wolves Legion, is drawn into the conflict, launching three successive counter-assaults in order to recapture the orbital hive stations' vital altitudinal control grid. Each fails to achieve its goal and countless thousands of Loyalist lives are lost. The famed Space Wolves grand cruiser, Helicon Spear, is captured and becomes a prize of the Iron Warriors Legion during the last, disastrous attempt.008.M31 Blood among the Pale Stars - A previously unidentified Blackshield group of unknown provenance, calling itself the Dark Brotherhood, carves out its own corsair empire on the edge of the Pale Stars and begins a long war against an Alpha Legion hunter-killer force tasked with crushing resistance to the Warmaster's Dark Compliance.008.M31 Ruin of Maerdan - In the third standard year of the Horus Heresy, the Imperial colony world of Maerdan on the edge of the Segmentum Solar became a savagely contested frontline between the forces of Loyalists and Traitors. Maerdan's cities became flaming ruins and its once verdant plains were turned to barren wastes, crushed and scoured by the fury of the battle as the Loyalist Titans of the Legio Gryphonicus ("War Griffons"), Legio Metalica ("Iron Skulls") and the Legio Destructor ("Beasts of Stell") clash with the Traitors of the Legio Mortis ("Death's Heads"), Legio Argentum ("Dread Lances") and the Legio Vulturum ("Gore Crows"). The Ruin of Maerdan, as the campaign comes to be known to later Imperial historitors, is one of the largest Titan battles of the early Horus Heresy, when more than 200 Titans took to the field against each other. Heavy losses were incurred by both sides and as the war moved on, it left a shattered world behind, with neither Loyalists nor Traitors able to claim a true victory. The flames of hatred between the War Griffons and the Death's Heads, once staunch allies, burn bright after Maerdan and their enmity would lead them to seek each other out time and again on the fields of battle in the dark years that followed their first clash.008.M31 Destruction of Bodt - The World Eaters' fief world and Legiones Astartes training ground on Bodt is attacked by Autek Mor of the Iron Hands and an allied independent Loyalist force. After a savage battle, Mor is believed to have entered the subterranean macro-vaults of the city of Tredecimmia before scouring every trace of life from the surface. Bodt's supply line of initiate recruits to the World Eaters Legion is permanently severed.008.M31 Burning Grave of Ohmn-Mat - The Forge World of Ohmn-Mat in the Ultima Segmentum falls into a state of civil war as its Synod Magos are split in their support for Loyalist and Traitor causes, drawing in contingents of Sons of Horus Dark Compliance forces and Iron Hands Isstvan survivors as the conflict escalates. Ohmn-Mat is destroyed in the conflagration and its fires still rage till the present.008.M31 Fall of Batzel III - Space Wolves strike forces eradicate the entire 39th Millennial of the Emperor's Children during the storming of the Vykstag Winter Palace as part of the Batzel III Campaign for control of the Brozyn-Primaris sector of the Segmentum Obscurus. Leaderless, Batzel succumbs to infighting and ultimately genocidal civil war. While exiting the sector, the Space Wolves strike force clashes inconclusively with an unknown and elusive Blackshield Legiones Astartes force which bears no recognisable heraldry.008.M31 Blight of Isessos - A series of void raids on the outskirts of the Isessos System in the Segmentum Pacificus by an Alpha Legion strike group leads to severe casualties, which are returned to the colony habitats of the system's three Agri-Worlds for treatment. Several of the casualties are later found to have been infected with an unknown algal strain. Within a year this virus wipes out the system's vast macro-output saturation fields, reducing them to poisonous slime. This results in a sector-wide famine that killed an estimated ninety billion Imperial citizens and the complete political destabilisation of the region.008.M31 Dagonet Incident - The hidden clade-masters of Terra's Officio Assassinorum dispatch their most potent assassins to the recently fallen world of Dagonet in an attempt to strike down the Warmaster Horus. They are unsuccessful, but from their failure Terra learns much of the new and dreadful powers drawn from the Empyrean that are wielded by its foe.009.M31 Breaking of Anvillus - The vital Forge Worlds of the Anvillus System erupt into a war of mutual annihilation. Strangely, the magi lords reject offers of alliance from both Loyalist and Traitor causes, instead destroying any who attempt to intervene. No onlookers are able to determine what the opposing factions are warring over, or why the conflict began.009-013.M31 Siege of Inwit - Dozens of Traitor fleets attack the systems of the Inwit Cluster, hungry for the prize of the Imperial Fists' homeworld. The siege increases steadily in intensity for four standard years before the Warmaster's direct assault on Terra draws Traitor forces away, leaving the Inwit Cluster a string of burning, wasted worlds.009.M31 Battle of Molech - Horus led both the Sons of Horus and the Death Guard Legions in the invasion of the Fortress World and Knight World of Molech. Having recovered some of his memories in regards to the earlier Imperial Compliance campaign that took place on Molech commanded by the Emperor many solar decades earlier, Horus uncovered the truth the Emperor had sought to keep even from his gene-sons about the hidden, subterranean Warp Gate present on the world that led into the Realm of Chaos and that the Emperor used millennia before to gain much of His secret knowledge and power -- including the arcane techniques required to create the primarchs. Wanting this power for himself, Horus launched a massive strike on the unsuspecting world. The Traitors committed an enormous invasion force, including the bulk of the Sons of Horus and Death Guard Legions, and Titans of the Legio Mortis ("Death's Heads"), Legio Vulcanum II ("Lords of Ruin"), Legio Interfector ("Murder Lords"), and Legio Vulpa ("Death Stalkers"), which were opposed by elements of the Ultramarines and Blood Angels Legions, Titans of the Legio Gryphonicus ("War Griffons"), Legio Fortidus ("Dauntless"), and Legio Crucius ("Warmongers"), and hosts of Knights from almost a dozen houses, with both sides bolstered by hundreds of thousands of allied mortal troops. At the height of the battle, House Devine revealed that its true allegiance was to the Warmaster, its treachery unveiled at a pivotal moment, heralding a slaughter from which only a handful of Loyalists escaped. The Warmaster went on to claim the world and enter the Warp Gate, from which he emerged fully empowered as the chosen champion of the four major Chaos Gods in the guise of Chaos Undivided. Later, a force of the elite Knights-Errant, a secretly founded order of Loyalist Space Marine agents, were despatched to Molech by Malcador the Sigillite, the Regent of Terra, to prepare the way for a direct assault by the Space Wolves against the Warmaster's flagship. Having recently won the full blessings of the Ruinous Powers while within the Realm of Chaos after transiting through the Molech Warp Gate, Horus proved undefeatable and only a handful of Knights-Errant, including Garviel Loken, managed to escape the corridors of the Vengeful Spirit to bring news of the Warmaster's redoubled strength back to an increasingly beleaguered Terra.009.M31 Tsagualsa Incident - Forces of the Dark Angels Legion ambush the Night Lords at Tsagualsa, inflicting severe losses. Lion El'Jonson of the Dark Angels and the Night Haunter clash in direct contest of arms after a failed parley, and both are so grievously wounded that their warriors are forced to drag them clear of each other before the matter can be settled.009.M31 Battle of Pharos - Upon the far-flung world of Sotha, which lay close to the edge of the galaxy's Eastern Fringe, almost at the limits of both the fiefdom of the Five Hundred Worlds of Ultramar and the span of all Imperial territory. Upon this world the Ultramarines had discovered beneath its tallest peak, named Mount Pharos, a massive aperture constructed by an unknown xenos species. This device functioned both as a beacon and route-finder, and it also permitted instantaneous communication across unimaginable distances, even penetrating the raging tumult of the Ruinstorm. Following their defeat at the hands of the Dark Angels at Tsagualsa, remnants of the Night Lords Legion followed this beacon in the warp, which guides them safely to the world of Sotha. Over many months, the Night Lords secretly gather intelligence on the suspicious activities of the Ultramarines, and soon discover the nature of the arcane device, named the Pharos, upon the restricted planet. The Night Lords launched a surprise assault upon the lightly garrisoned world, intent on seizing the Pharos in order to use it to determine the location of their flagship, the Nightfall, as well as the whereabouts of their missing Primarch Konrad Curze. In the ensuing battle, the loyalist Iron Warriors Warsmith Barabas Dantioch, sacrifices himself by overloading the Pharos, so that the Night Lords would be unable to utilise the device's powerful empathic abilities. What far reaching consequences this will have for the galaxy, will not come to pass for another ten millennia.009.M31 Xana Incursion - Intelligence reaches Terra that the Traitor Forge World of Xana II on the western fringe of the Imperium has reached an accord with the Traitor forces to supply the Warmaster's armies with its vast output of arms and materiel. The bargain is sealed with the delivery by Xana of a number of newly created powerful Ordinatus class weapons undergoing final field tests. In what is effectively a suicide mission, a handpicked force of Legiones Astartes, including many Blackshields -- in this case Space Marines who have chosen to remain loyal despite their parent Legion's treachery -- is despatched under great secrecy to destroy the war machines and drive a wedge between Xana and the Traitors.009-053.M31 Carnage of Morox - In one of the largest confrontations between Loyalist and Traitor-aligned auxilia and militia forces, in excess of three billion battlefield fatalities are recorded as the death toll from a grinding war of attrition on the sector-capital world of Morox Excellus. The Morox civil war takes place in almost total isolation owing to turbulent Warp Storm activity and lack of any real strategic significance to either side of the wider conflict, and is noted for the exponentially increasing levels of atrocity and rapid technological regression of the conflict.009.M31 Battle of Arissak - Having pursued the numerous attack cells made up of Iron Hands, Salamanders and Raven Guard survivors of Isstvan V, Captain Tybalt Marr of the Sons of Horus finally brings them to battle, destroying the massed fleet of [[Shadrak Meduson's so-called "Shattered Legions" force at Arissak.009.M31 Incident at Dwell - Having escaped death at Arissak, one of Shadrak Meduson's surviving Shattered Legion attack cells launches a daring assassination attempt on Warmaster Horus at Dwell. With his brother-Primarchs Fulgrim and Mortarion at his side, Horus prevails, but having had the true threat revealed to him grants Tybalt Marr permission to take any action he deems appropriate to eradicate the so-called "Shattered Legions."009.M31 Sangraal Campaign and the Salvation Run - A hand-picked Imperial Fists assault force despatched from Terra launches a daring raid to capture the antidote to a slow-burning Exterminatus-class viral weapon deployed against the Loyalist holdfast of Gramercie on the contested Hive World of Herkaliaum. After recovering the antidote stocks from the Traitor Mechanicum-Bioligis gene-labs, the heavily outnumbered Imperial Fists then fight their way through massed Traitor forces, running a deadly gauntlet through the underhives of Herkaliaum to deliver the antidote to Loyalist medicae detachments, thus saving the population of the Gramercie sub-hive. Viral overspill ravages the Traitor forces now unable to contain or cure the contagion in their own ranks, and within weeks, Herkaliaum is liberated. The legend of the "Salvation Run" becomes a rallying cry for Loyalist support in the sector, turning the Sangraal Campaign in the Loyalists' favour and cementing their hold on the Segmentum Solar.009.M31 Establishment of the Imperium Secundus - With the Imperium severed in two halves, isolated and ignorant of each other as a result of the raging tumult of the Ruinstorm, the light of the Astronomican is no longer visible from Ultramar and no word of the Emperor has been heard for several years. Ultramarines Primarch Roboute Guilliman declares the foundation of the "Imperium Secundus" as a means of continuing the fight against the Traitors and securing the Emperor's great work. When the Blood Angels arrive at Ultramar having escaped the Signus Cluster, Guilliman proclaims Sanguinius as the rightful heir to the Emperor. [Extract sanctioned for data purge]010.M31 Scouring of Gilden's Star - Scattered elements of the Blood Angels Legion fight a long and bloody campaign against Word Bearers forces near the galactic core on the borders of Imperium Secundus that culminates in the near-total destruction of both armies. During the campaign, the Blood Angels prove merciless in scouring worlds which have embraced the daemonic teaching of the "dark apostles" of the Word Bearers, putting all seven colonised worlds of Gilden's Star to the sword in one particularly notable instance.010.M31 Battle of Nycron - Under the direction of Imperial Fists Primarch Rogal Dorn, a Loyalist battlegroup led by elements of the Salamanders Legion, and supported by thirty regiments of the Imperialis Auxilia and a strike force of Legio Astorum Titans, engage an Emperor's Children millennial assigned to garrison the Beta-Garmon System on the edge of the Segmentum Solar. The Emperor's Children contingent is surprised at Nycron City on Beta-Garmon II and after a hard-fought battle, the Emepror's Children forces along with their Legio Mortis allies at Beta-Garmon III are driven out, placing the system into Loyalist hands and triggering within the year the first of an escalating series of Traitor counter-attacks with the goal of retaking Beta-Garmon as a stepping stone for an eventual attack on Terra. Ultimately, these will only serve as a prelude to the far greater conflict in the system to come.010-012.M31 Fate of the Sabalis Liberatus - The Sabalis Liberatus, a Raven Guard Legion battlecruiser lost in the Warp since escaping the void battle over Isstvan V, finally breaks into realspace near Galaspar on the borders of the Veiled Region on the southern galactic fringe. The survivors on board, comprising a mixture of Loyalist Legions, have spent the time in self-imposed suspended animation and awoke to find themselves utterly cut off from information or support. Fired on by Imperial patrol vessels whose captains have sided with the Traitors, this "Shattered Legion" force boards the patrol vessels and conquer their attackers. Effecting repairs from the captured ships, they begin a further two-year odyssey of battle to return them to the Segmentum Solar and finally Terra, where they will ultimately fight in the void battles against the Traitor onslaught in the closing days of the war.010-012.M31 Battle of Tallarn - Tallarn, an Imperial muster world of almost unparalleled size and importance, comes under direct attack by the Iron Warriors Legion after their emergence from the Eye of Terror in an attempt by Perturabo to retrieve a powerful Chaos artefact hidden beneath the planet's surface. Perturabo's Legion is bolstered by dozens of allied Traitor Imperial Army regiments, the Titans of the Legio Krytos ("God Breakers") and the Knights of House Caesarean. Both the Loyalist and the Traitor high commands are taken by surprise by Perturabo's actions and the invasion quickly escalated after he ordered an Exterminatus action upon the world, scouring its surface of living matter by way of a voracious Life-Eater viral barrage that rendered the surface of the once-verdant world of Tallarn poisoned slime and makes the air unbreathable. While the population is all but wiped out, many defenders survived thanks to the existence of extensive subterranean shelters. The ensuing campaign is fought between vast formations of Imperial Army and Solar Auxilia tanks, the Titans of the Legio Gryphonicus ("War Griffons"), the Knights of House Megron, the indentured automata of the house army of the Rogue Trader Sangrea as well as the armoured forces of the Iron Hands, Imperial Fists, White Scars and Ultramarines Legions. No infantry can survive in the poisoned wastes of Tallarn, and most of the vehicles that do fight have been environmentally-sealed. As the conflict grinds on, it draws in Loyalist and Traitor forces from hundreds of worlds across the entire Segmentum Tempestus before its cataclysmic conclusion and the subsequent retreat of the Traitor forces. The Battle of Tallarn is now considered the largest armoured engagement in the known history of Humanity, and while counted as a victory for the Loyalists, millions of warriors and war machines on both sides were left scattered across the lifeless, deadly surface of the planet. Tallarn will be reclassified in the wake of the battle as a Desert World.010.M31 Cataclysm of Iron Begins - Across the sectors of the Segmentum Tempestus and Segmentum Pacificus are located numerous Forge Worlds known collectively as the "Belt of Iron." Since the sundering of the Imperium, many of their number have declared for the Traitor cause at the engineering of the fabricator-general of Mars, while others have remained loyal to Terra or in some cases sought to remain aloof from the conflict as much as possible. Strife and tentative conflict between these once-aligned worlds erupts finally into full scale war in 010.M31, which pitches the Mars-aligned Forge Words of Incunabula, Urdesh, Valia-Maximal and Kalibrax against the forces of Loyalist Forge Worlds Graia, Arl'yeth and Atar-Median, while Arachnis and Jerulas Station both fall into the anarchy of civil war. The resulting conflict, that later becomes known as the Dispute of Iron, sees the forge lords, their armies and allied Titan Legions and Knight Households turn on each other in protracted warfare, with scores of human-inhabited worlds in the region suffering as they become the battlegrounds upon which they fight.010.M31 Battle of Pluto - The Alpha Legion carries out multiple diversionary attacks of sabotage and preparation as part of the broader Solar War, which plunges the Sol System into complete chaos. Their true target, however, is the fortress moon of Hydra, which orbits Pluto. First Captain Sigismund and a small fleet of Imperial Fists stubbornly defend Pluto against the larger Alpha Legion fleet until help arrives, in the form of the great mobile star fort Phalanx and a large fleet of Imperial Fists and Armada Imperialis warships. At the height of the battle, the Primarch Rogal Dorn, the Praetorian of Terra, led an assault on the fortress moon and confronted his brother Primarch Alpharius and engaged him in melee combat. Alpharius was slain by Dorn, and the Alpha Legion forces were forced to withdraw.010.M31 Battle of Nycron - Under the direction of Imperial Fists Primarch Rogal Dorn, a Loyalist battlegroup led by elements of the Salamanders Legion, and supported by thirty regiments of the Imperialis Auxilia and a strike force of Legio Astorum Titans, engage an Emperor's Children millennial assigned to garrison the Beta-Garmon System on the edge of the Segmentum Solar. The Emperor's Children contingent is surprised at Nycron City on Beta-Garmon II and after a hard-fought battle, the Emperor's Children forces along with their Legio Mortis allies at Beta-Garmon III are driven out, placing the system into Loyalist hands and triggering within the standard year the first of an escalating series of Traitor counterattacks with the goal of retaking Beta-Garmon as a stepping stone for an eventual attack on Terra. Ultimately, these will only serve as a prelude to the far greater conflict in the system to come known as the Battle of Beta-Garmon.010-013.M31 Grand Imperial Muster and the Battle of Beta-Garmon ("The Titandeath") - For reasons only understood later in the war, the Ruinstorm that had been summoned by the Primarch Lorgar's servants among the Word Bearers Legion several standard years before during the Battle of Calth began to abate across vast swathes of the galaxy, reopening astropathic communications and transport routes to Terra. Loyalist high commanders were able to utilise the potent astropathic relay located in the Beta-Garmon System to contact and recall formerly lost or stranded Imperial forces from across the wartorn reaches of the northern Imperium. The Imperial muster at Beta-Garmon rapidly escalated into the largest gathering of Loyalist might since the early years of the civil war, a concentration of force so mighty that the Traitors were forced to respond in kind. The resulting clash of arms, the Battle of Beta-Garmon, would also become known as the "Great Slaughter," a theatre of war of such scale that it would encompass the Titandeath and the Sea of Fire campaigns, each major battles in their own right. The conflict saw billions of lives lost, thousands of starships destroyed, and the might of the Collegia Titanica all but broken. By its end, both sides were so badly bled that their only remaining option for ultimate victory was to force a final, decisive confrontation. As history relates, that final battle would be fought at Terra, but only after the weighty butcher's bill of the Great Slaughter was paid in full...011-013.M31 Lorin Alpha Campaign - The White Scars and Emperor's Children conduct a high-speed duel across the last critical space lines connecting Terra to the northern Imperium. The aftermath of the Battle of Beta-Garmon brings Dark Mechanicum forces and the Sons of Horus to the planet, turning the tide against the White Scars and ultimately ejecting the Loyalists from Lorin Alpha.011.M31 Malagant Conflict - While surviving Loyalist enclaves apparently crippled by the Warmaster's onslaught, those Death Guard elements assigned to the garrison of Barbarus spearhead an assault into the southern reaches of the Imperium. The grim warriors of Barbarus made the vast industrial hives of Malagant their prime target, a world made valuable for the strategic worth of its manufactoria, and to crush the defiance of the surrounding sectors, many of whom looked to the determined Loyalist leaders of Malagant for leadership. Yet where the Death Guard had expected to crush the Malagantine auxilia in short order, they found themselves mired in cunning ambushes and punishing counter-attacks led by Legiones Astartes bearing the sable mark of the Raven Guard. Lacking the numbers to meet the Traitors head-on, the sons of Corax plied their deadly skills as skirmishers and assassins upon their erstwhile brothers; trapping them on a world they could not afford to abandon, battling a foe they could not pin down and crush. For three years, little more than a company of Raven Guard occupied an augmented chapter of Barbarus' finest, until 014.M31 when the Death Guard retreated in the face of approaching Loyalist reinforcements from Inwit.011.M31 The Marches of Madness - The World Eaters made seemingly senseless raids on population centres across the Ultima Segmentum. Their brutal attacks are aimed at causing maximum Human casualties, ignoring both infrastructure and military targets. The attacks are accompanied by unseasonal violent storms and unnatural crimson cloud bursts, all indications of increased Empyreal activity wherever the World Eaters go. By this time in the Heresy, the World Eaters have come fully under the grip of Khorne and now seek only more blood for the Blood God's unending thirst, no longer even trying to pursue rational tactical or strategic objectives.011.M31 Second Battle of Paramar - Paramar V had fallen to the Warmaster Horus' hosts in the opening moves of the Horus Heresy. In response, a mixed force of Loyalists launched an assault against the strategically vital supply nexus with the intent of denying it to the Traitors' war effort. The Traitors numbered a substantial combined forces of Legio Fureans ("Tiger Eyes") and Legio Mortis ("Death's Heads") god-engines that were in the system re-arming and re-supplying after several standard years of intensive campaigning, and a large presence of Sons of Horus and Word Bearers Heretic Astartes. The Loyalists committed a large Titan force drawn from the Legio Atarus ("Firebrands"), Legio Ignatum ("Fire Wasps") and Legio Solaria ("Imperial Hunters"), with ground assault units of the Blood Angels and White Scars Legions. The Loyalists conducted a series of diversionary attacks across the Paramar System in order to draw Traitor forces away from their true target, before they conducted a full-scale planetstrike against Paramar V's primary spaceport, capturing it intact and then pressing outwards to begin the destruction of the mass-provender silos that sprawled across the plateau beyond. It was soon revealed, however, that the Traitors had seen through the Loyalist ploy and prepared a huge counter-attack force. Though the Loyalists inflicted heavy damage on the provender silos before the counter-attack hit home, the vast majority of the Loyalist invasion force was surrounded and destroyed without mercy.Battle of Ice World Tralsak (011.M31) - The shallow, frozen oceans of the Ice World of Tralsak were flash-boiled to steam by the fury of god-engine war as the Loyalist Titans of the Legio Atarus ("Firebrands") and the Legio Agravides ("Battle Scourges") clashed with the Traitors of the Legio Magna ("Flaming Skulls") and Legio Victorum ("Foe Slayers") as Loyalist Shattered Legions and Traitor World Eaters Astartes fought across the disintegrating landscape of ice floes. Ultimately, outright victory eluded both sides, and each used the cover of the world-enveloping fog thrown up by the destruction to extricate their forces and redeploy them elsewhere. Nevertheless, numerous supporting Knights of both sides remained to fight a war in which neither side conceded defeat.Tarren Suppression (011.M31) - The world of Tarren IV declared for the cause of Horus, its rulers having fallen for the honeyed words of the Warmaster's emmisaries. A Loyalist Retribution Fleet moved quickly to crush the treachery, and its forces occupied Tarren IV's capital city of Brandstat and stamped out anti-Imperial sentiment in a brutal mirror of the Traitors' so-called "Dark Compliance" of conquered worlds. The key to the suppression were the Titans of the Legio Defensor ("Nova Guard"), who bestrode the surface of Tarren IV, the mournful dirge of their war sirens demanding submission to the Emperor and making examples of those cities that refused to do so by blasting them into flaming ruins. As if to mock the expected order of things still further, later on, it was an allied force of the Emperor's Children Legion, the Legio Cybernetica and the Legio Mortis ("Death's Heads") that conducted a heavy planetary landing and "liberated" the world from the Loyalists during the campaign known to the people of Tarren IV as the "Relief of Brandstat."011.M31 Battle of Zepath - Obsessed with hunting down his brother the Night Haunter, the Primarch Lion El'Johnson eventually is able to trace a slim lead on his brother's whereabouts to the Zepath System, which had since fallen to the forces of the Word Bearers and World Eaters. Farith Redloss, the Lieutenant-elect of the Dark Angels' Hexagrammaton Dreadwing formation, was charged with leading the hunt for Konrad Curze upon the world of Zepath. The Dark Angels quickly uncovered the horrors perpetrated by the Word Bearers to fuel their dark Chaos rituals. Eventually, the Dark Angels took part in multiple engagements against the forces of both Traitor Legions, which culminated in the Zepathian capital city of Numentis. The Traitor forces were utterly annihilated by the victorious Dark Angels. The world was left in the care of its surviving population.011.M31 Scouring of the Nostramo Sector - In 017.M31, after the end of the Horus Heresy, a Retribution Fleet designated "Battlefleet Vengeance," led by the Blood Angels' 33rd Company, 9th Chapter, launched a campaign into the Nostramo Sector for further vengeance in their lost Primarch Sanguinius' name, against remaining active Night Lords combat units within the sector. Yet despite all intelligence to the contrary, no determined resistance was to be encountered by these fleets. Of the VIIIth Legion, only scattered and isolated warbands were discovered, and none larger than a reinforced company. They soon uncovered, on multiple, formerly Night Lords-held worlds, evidence that an unknown Blackshield force had ravaged the Nostramo Sector in 011.M31, leaving nothing but ruined fortresses and drifting battle-scarred wrecks of the VIIIth Legion in their wake. It wouldn't be until 017.M31 that this Blackshield force would be identified as the mysterious Ashen Claws.012-013.M31 Passage of the Angel of Death - Freed from their isolation by the abating Ruinstorm, the Dark Angels wreak havoc in a campaign of revenge against any loyal to Horus. A trail of blackened, scorched worlds is left in their wake across the southern Imperium, including the homeworlds of the Emperor's Children and Death Guard Legions, the Chaos-corrupted worlds of Chemos and Barbarus, respectively.012.M31 Balthor Sigma Intervention - A blood-maddened pursuit force of Traitor World Eaters Astartes engaged in hunter-killer operations against defeated Loyalist forces was counter-attacked by a Legio Osedax ("Cockatrices") demi-legio at the world of Balthor Sigma. The World Eaters are supported by numerous super-heavy tanks and therefore are able to hold the Cockatrices Titans at bay until, in quick succession, the Traitor tanks are engaged from an unexpected quarter and destroyed in short order. Entirely unheralded, a force of xenos Titan-analogues, later determined to belong to the Eldar, intervened to devastating effect. It was only when Traitor-aligned Titans of the Legio Fureans ("Tiger Eyes") fought their way through to reinforce the Traitors' lines that total defeat for the Warmaster's servants was averted. At the conclusion of the battle, the xenos Titans disengaged and vanished into the ash-shrouded depths of Balthor Sigma's equatorial magma wastes.012.M31 Birth of the Adeptus Mechanicus - A long-running political deadlock in the Council of Terra back on the Throneworld of the Imperium is finally broken, facilitating the formal establishment of the Imperial Adeptus Mechanicus. The Adeptus Mechanicus is recognised as officially separate and distinct from the corrupted Mechanicum of Mars. Fabricator-General Zagreus Kane is appointed its first High Lord of Terra to serve on the council. Final judgement is enacted upon the captive followers of the Traitor Fabricator-General Kelbor-Hal of the Dark Mechanicum, who are executed in their thousands. Immediately after, the union of Loyalist Titan Orders, under the umbrella of the Adeptus Titanicus or Collegia Titanica, is formed by the grand masters of several major Loyalist Titan Legions, although the future of other loyal former Mechanicum divisions such as the Legio Cybernetica and the regular military forces of each Forge World's Taghmata remains unclear.012.M31 Battle of Yarant - After an ill-counselled assassination attempt against the Warmaster Horus, the scattered Space Wolves are pursued to the Yarant System, where they make a desperate last stand. Leman Russ' many enemies press his Legion to near-extinction, and the Space Wolves are only saved by the unexpected intervention of Corvus Corax and the Raven Guard.012.M31 Scouring of the Ollanz Cluster - The Warmaster Horus' advance on Terra eventually reached the Ollanz Cluster, where he encountered Loyalist reinforcements bound for Beta-Garmon rearming and refuelling at the Borman System. The Loyalist fleet rapidly redeployed to oppose the Traitors' advance and to protect the valuable resource worlds of the stellar cluster. The turning point of the brief but intense conflict came at Borman IV, when a Legio Astorum ("Warp Runners") demi-legio launched a daring offensive towards the world's beleaguered capital city. The crucial Titan battle took place in the volcanic Yrevendi Desert immediately to the north of the capital, as Princeps Senioris Varr Harax led a surprise thrust through rough terrain at a weak point in the Legio Fureans ("Tiger Eyes") lines, accompanied by Astartes ground forces drawn from the Iron Hands Legion. The Tiger Eyes, having been drawn away by a bold diversionary attack, were annihilated by the Warp Runners, who were able to break through the Traitor Emperor's Children Legion's lines and reinforce the beleaguered planetary capital. Ultimately, Borman IV and the entire Ollanz Cluster were delivered from the Traitors' possession, which allowed the Loyalist forces to be redeployed to their original destination at Beta-Garmon.013.M31 Return to Honour - Arcaes Odenathus, a captain-praetor of the Ultramarines 10th Chapter, rallies the scattered survivors of his own brethren and those other Loyalist fighting across the Dominion of Storms in the galactic north-east and lead them to Honourum. Unexpected and unlooked for, this Loyalist assault strikes the Word Bearers garrison on that world like a thunderbolt. Three solar weeks of desperate fighting ensues, and as all the Word Bearers' urgent requests for reinforcements are ignored by the Warmaster, focussed now on his push toward Terra, the sons of Lorgar resort to the most heinous of tactics. Daemons, warp-tainted infiltrators and terrors of the wars of Old Night are unleashed, with both sides driven on past mortal endurance by hatred. When the last Traitor finally fell, there was nothing left of the grand cities of Honourum but blasted ruins; ruins whose very substance was so contaminated by the fell powers and terrible weapons they unleashed that they would blight Honourum longer than the memory of the wars which spawned them.013-014.M31 Serpent's Coil - Despite the apparent death of their primarch at the Battle of Pluto, the Alpha Legion defy Horus' orders and set out to hinder Loyalists approaching Terra, seeking Ultramarines vessels in particular. Roboute Guilliman's fleet is forced to intervene to prevent further losses of vital reinforcements, critically delaying his arrival at Terra in time for the upcoming siege.014.M31 Siege of Terra (Battle of Terra) - The Siege of Terra, also called the Battle of Terra, is the final epic and cataclysmic campaign of the Horus Heresy. Many of the Loyalist Astartes Legions had been waylaid by the forces of the Traitor Legions loyal to the Warmaster and were unable to make their way towards Terra. The Imperial Fists had already returned to the cradle of humanity and under the stern gaze of their Primarch Rogal Dorn had adequately prepared Terra's defences as best they could. Jaghatai Khan, of the White Scars Legion, had also managed to make his way to Terra with his Legion to help with the defence of the Imperial Palace. The Blood Angels Legion were also able to make the Warp jump to Terra in time to meet the oncoming Traitor invasion. Three entire Titan Legions of the Mechanicum and close to 2 million soldiers of the Imperialis Auxilia stood alongside them to face the hosts of Chaos in a battle that would determine the fate of Mankind for the next ten millennia. Yet for all the might of the Emperor, for every effort of Sanguinius and the remaining Loyalist primarchs, the forces of Horus drove all before them. In too short a time, the Emperor of Mankind was assailed within his great palace on Terra. The siege of Terra following the initial assault on the Imperial Palace lasted for fifty-five days. Both sides knew that victory or defeat for the Imperium of Man was at hand. Inexplicably, the Warmaster lowered his void shield aboard his flagship, the Vengeful Spirit, and so, the Emperor rose to the challenge, and with Sanginius and Rogal Dorn at His side, along with a detachment of Legiones Astartes from Legions, as well as a the Emperor's personal guardians, the Legio Custodes. When the Loyalists teleported aboard the flagship, they were all separated by the Warmaster's fell powers and scattered throughout the massive warship. It was the Emperor who first arrived to the bloody scene in the Warmaster's throne room -- the winged corpse of the angelic Sanguinius lay at Horus' feet. Father and son fought one another in a titanic struggle, the fate of all of humanity hanging in the balance. In the end, the Emperor slew his former favoured son, but was mortally wounded during the vicious fighting. The Traitor Legions were routed and chased into the hellish realm of the Eye of Terror, while the Emperor was saved by the arrival of Rogal Dorn. Upon the Emperor's final instructions, he was placed into the confines of the great prosthetic, arcane device known as the Golden Throne, and spoke no more. Humanity prevailed, and the Imperium would live to endure, but paid a terrible price for their victory.