|Ambiguous Term? This article is about Horus Heresy historical period. For other uses of Horus Heresy, see Horus Heresy (disambiguation).|
The Horus Heresy, also known as the Age of Darkness, was the first and most devastating civil war in Imperial history. Occurring in early M31 and lasting several years, it divided and nearly destroyed the fledgling Imperium. It marked the end of the Great Crusade and the encasing of the Emperor of Mankind into the Golden Throne.
Though the Heresy was ignited by the product of a conspiracy by the forces of Chaos, there were precipitating factors that helped push many of the Legio Astartes towards rebellion. The first was the Emperor's return to and seclusion on Terra, working on a secret project that he refused to share with any of his Primarchs, including his most favored son Horus, whom he had named Warmaster. This apparent abandonment of the Great Crusade, for something he would not even share with his sons bred mistrust, resentment, and disappointment towards the Emperor amongst many of the Primarchs.[2a]
Another contributing factor was the formation of an administrative body known as the Council of Terra. Many of the Primarchs viewed these human bureaucrats as usurping their rightful place as rulers of the Imperium they had fought so hard to create. Worse still, the Primarchs were denied a place on the Council and the notion of an Imperium dominated by human bureaucrats, not the sons of the Emperor and their Astartes Legions, became a cause of concern for many of the Primarchs.[2a]
Lastly, the Emperor's disciplining of Lorgar and the Word Bearers was a contributing factor to the Heresy and the event which set it directly into motion. After Lorgar and the entire Legion were publicly humiliated, scolded, and forced to kneel in front of the Emperor for spreading their belief that the ruler of mankind was a divine being, the pious Word Bearers felt betrayed and desperately sought any power in the universe to worship. This eventually led Lorgar and his Legionaries to the Eye of Terror, where they pledged themselves to the forces of Chaos and began to conspire against the Emperor. Thus the Word Bearers had secretly become the first Chaos Space Marines. Secretly planning to make war on the Emperor, the Word Bearers quietly established Warrior Lodges with their Chaplains throughout the rest of the Astartes Legions. Though harmless at first glance, many of these lodges would become hotbeds of support for Horus' rebellion in the war to come.
However, the Horus Heresy truly began after Warmaster Horus was wounded by the possessed Eugen Temba wielding the stolen Anathame on the moon of Davin, a place that was cursed by the foul Chaos God Nurgle. The wound caused by the blade refused to heal, despite Horus's super-enhanced immune system or the efforts of the Sons of Horus's best apothecaries. The Mournival took Horus to the Davinite Serpent Lodge, which they were told could heal him. Erebus and the Word Bearers had orchestrated the battle on Davin, unknown to all involved.[Needs Citation]
During the rituals, Horus's spirit was transferred into the Warp where Erebus, disguised as the Warmaster's closest friend Hastur Sejanus, showed him a terrible vision of the very future which his actions would bring about - the Imperium as a repressive, violent, and superstitious regime where the Emperor and some of the Primarchs (but not Horus) were worshiped as divine beings by the fanatical and ignorant masses of humanity. The Chaos Gods portrayed themselves as the victims of the Emperor's psychic might who had no interest themselves in controlling the material world. Horus, already having grown jealous and deeply resentful of his perceived poor treatment at the hands of his father, the Emperor, and was one of many afraid of the concept of a peace where all for which that they had fought was given to weak willed men whilst his legions were cast aside and left as peacekeepers. Horus therefore proved all too willing to accept the Ruinous Powers' false visions of an Emperor determined to make himself a god at Horus's expense.[Needs Citation]
But there was one thing no one had counted on: Horus's brother Magnus the Red, Primarch of the Thousand Sons, had continued to study the forbidden arts of sorcery, and was not about to let his brother fall to the powers of the Warp. The cyclopean giant appeared within Horus's vision, revealing the chaplain's identity and begging Horus not to give in to the temptations of Chaos. Unfortunately, Horus had decided that if anyone deserved to be worshipped as a god it was he, and not the Emperor. He accepted the offer of the Chaos Gods to join their cause and in return they healed his wound and granted him the powers of the Warp. The Chaos Gods' pact with Horus was simple: "Give us the Emperor and we will give you the galaxy."[Needs Citation]
Swaying the LegionsRenouncing his oath to the Emperor, Horus led his Legion into worship of the myriad Chaos Gods. Horus's genius was revealed as he converted half of the Legions, along with many regiments of the Imperial Army and several Titan Legions to his cause, revealing the Emperor to be as Horus saw him - a man undeserving of the praise and recognition of the human race.[Needs Citation]Angron of the World Eaters, Fulgrim of the Emperor's Children and Mortarion of the Death Guard were the first Primarchs to side with the Warmaster. Horus found it easy exploit the Primarchs' flaws - Angron's frenzied love of violence was a match for Khorne; Fulgrim was corrupted by a daemon weapon of Slaanesh and its promise of unending perfection; Mortarion, already a close friend of his brother, was too easily persuaded, having been turned long before the Heresy through the efforts of his first captain Calas Typhon. Erebus had already vouched for the support of Lorgar and the Word Bearers, and Horus's plans came together with these legions at his side.[Needs Citation]Magnus, however, had yet to be dealt with. The Primarch was aware of his brother's fall and attempted to warn the Emperor of the impending betrayal. However, knowing that he would have to find a means of quickly warning the Emperor, Magnus decided to use his sorcery to deliver the message as an act of both desperation and vindication. The message penetrated the psychic defences of the Imperial Palace on Terra, shattering all the psychic wards the Emperor had placed on the Palace and destroying his secret project: a physical gate by which the Emperor intended to invade the Webway and take battle to the Eldar.[Needs Citation]
Magnus's brute force assault on the wards allowed the Warp and its myriad inhabitants to invade Terra. In the City of Sight, the tremendous rush of raw psychic energy obliterated the Choir Primus and shattered nearly every whisperstone. Millions died as their minds were burned out or daemons tore them apart. Warp storms consumed entire settlements. Shockwaves flattened structures around the world. Having already outlawed the Primarch's use of sorcery and refusing to believe that Horus, his most beloved and trusted son, would betray him, the Emperor instead perceived the traitor to be Magnus and his Legion. The Emperor ordered the Primarch Leman Russ to mobilise his Space Wolves Legion and take Magnus into custody; Horus, however, persuaded Russ that Magnus was a threat and should not return to Terra alive. The Wolves of Fenris descended upon Prospero, destroying all in their path. Magnus, betrayed, defeated and forsaken by his beloved father, retreated into the Warp and pledged himself to Tzeentch. The Thousand Sons had never planned to join Horus, but the trap that the Changer of Ways had laid for the Red Sorcerer's legion led them to the Warmaster's side regardless. Meanwhile the catastrophe on Terra forced the Emperor to deal with a new crisis that consumed most of his attention. He led the Custodes and Sisters of Silence to deal with this, while he left management of the rebellion to Malcador and Rogal Dorn.
Of the other eventual traitors, Konrad Curze was due to face disciplinary action from the Emperor for his excessive bloodshed on Nostramo; Alpharius chose to join Horus after an ancient cabal of aliens revealed a prophecy to him that Horus's victory would cause the downfall of the Chaos powers; and Perturabo's cold nature and bitterness towards Rogal Dorn made him an easy target for corruption. Even with so many legions on his side, Horus was still aware that some of his brothers would never join him. Three of the most loyal Primarchs, Lion El'Jonson of the Dark Angels, Sanguinius of the Blood Angels, and Roboute Guilliman of the Ultramarines, were sent on missions far from Terra. The Blood Angels were sent to the daemon-infested Signus Cluster and the Ultramarines to Calth, where Kor Phaeron attacked the loyalists with a large force of Word Bearers and millions of Chaos cultists. Unbeknownst to the Lion, a rebellion was soon to occur on his homeworld of Caliban while the bulk of his legion was bogged down battling the Gordian League.
The Imperial Fists and White Scars were too close to Terra to be contacted without raising suspicion, though Horus believed (mistakenly) that Jaghatai Khan would ultimately take his side. Shortly before the Dropsite Massacre, Horus also ordered Fulgrim to turn Ferrus Manus to their cause, but the Phoenix underestimated the Gorgon's loyalty and barely escaped alive. Fulgrim promised he would deliver Manus's head to Horus in recompense.[Needs Citation]The remaining Legions - the Raven Guard, Salamanders, Iron Hands and Space Wolves - remained staunchly loyal to the Emperor, though all but the Wolves would pay dearly for it in the battles to come. Beyond the Legions, Horus had already swayed Adept Regulus with promises of the STCs recovered during the war with the Auretian Technocracy, delivering Adeptus Mechanicus support to the Warmaster's forces, and had corrupted a large portion of the Imperial Army and Navy.[Needs Citation]
Scouring of Isstvan III
The first sign that Horus and his Legion had turned to Chaos was made evident when Horus virus bombed the rebel world of Isstvan III. The Planetary Governor of Isstvan III had declared his independence from the Imperium and the Council of Terra charged Horus with retaking that world. This order merely furthered Horus's plans. Although the four Legions under his direct command had turned traitor, there were still some loyalist elements within the Sons of Horus, World Eaters, Emperor's Children, and Death Guard; many of these were Terran Space Marines who had been recruited before being reunited with their Primarchs. Horus, under the guise of his orders, amassed his troops in the Isstvan System.[Needs Citation]
Horus had a plan by which he would destroy all loyalist elements of the Legions at his command. After a lengthy bombardment, Horus dispatched all Loyalist Marines down to the planet, ostensibly to bringing it back into the Imperium. At the moment of victory, however, the loyalist marines were betrayed: with a cold snarl of "Let the galaxy burn!, Horus ordered his ships to open fire on Istvann III and virus bombs began to rain down on the planet. However, some marines loyal to the Emperor had remained on board their ships, and as Isstvan III died, these soldiers fought desperately to warn their brethren on the surface. Their sacrifice saved many marines, as they were able to take shelter before the virus bombs struck. The population of Isstvan III received no such protection. Twelve billion people died almost immediately. The psychic shock of so many simultaneous deaths shrieked through the Warp, alerting the Emperor that something was terribly wrong and informing the Chaos Gods that Horus was now theirs. A contingent of loyalists led by Captain Garro of the Death Guard escaped the fleet orbiting Isstvan III aboard the damaged Eisenstein, fleeing to Terra to warn the Emperor.[Needs Citation]Angron, realising that the virus bombs had not been fully effective against the loyalist marines, flew into a rage and hurled himself at the planet with fifty companies of World Eaters. Horus was furious at Angron for delaying his plans, yet reluctantly reinforced him with troops from the Sons of Horus, the Death Guard, and the Emperor's Children. On Isstvan III, the remaining Loyalists under the command of Saul Tarvitz fought bravely against their own traitorous battle-brothers, but their cause was doomed. Soon only a few hundred of them remained until, finally, Horus grew unable to tolerate the delay, forced Angron to withdraw his forces, and ordered a systematic orbital bombardment that killed Isstvan III's last brave survivors.[Needs Citation]
Flight of the Eisenstein
The seventy Loyalists led by Captain Garro commandeered the Imperial frigate Eisenstein and evading the forces of Horus, were able to escape from the Isstvan system into the Immaterium. The Eisenstein was badly damaged during its escape from Isstvan III; all its astropaths were dead and its lone navigator was mortally wounded. However, Garro managed to attract the attention of passing loyalist ships by setting the vessel's warp engines to self-destruct and ejecting them from the ship. Rogal Dorn's Imperial Fists Legion had been becalmed in the Warp with its fleet for some time and his navigators sensed the detonation of the Eisenstein's Warp drives. Making an immediate course for the location of the ship's beacon, Dorn met with Garro, who explained to him all that had happened with the traitor legions.[Needs Citation]
The remaining crew of the Eisenstein, now aboard Primarch Dorn's fortress-monastery Phalanx, was able to reach Terra (after Dorn's fleet destroyed the Eisenstein to ensure no Chaos taint remained), allowing the loyal marines to report the extent of the atrocities that had occurred in the Isstvan system. It was said in later millennia that without this warning, the Imperium would have faced even greater difficulties in responding to Horus's next moves although his warning may have enabled Horus to enact the drop site massacre.[Needs Citation]The fate of these seventy marines is ultimately unknown. Some believe they continued to fight for the Emperor until death claimed them, while others maintain that they were treated as if they were their traitorous brethren, either imprisoned and left to rot or executed. Others believe that Captain Garro, shocked by the terrible betrayal, became an apothecary, vowing never to kill again. Others believe some of these men formed the nucleus of the elite Space Marines Chapter later known as the Grey Knights, for Malcador the Sigillite had presented eight of the survivors to the Emperor before his departure. These men were gifted psykers, came from the ranks of the Legions that had turned traitor, and yet maintained both an unbreakable faith in the Emperor and talent for resisting the temptations of Chaos.[Needs Citation]
Drop Site Massacre
After ridding himself of all suspected loyalist members within the three Legions under his direct command, Horus chose Isstvan V as his command post and prepared a trap for his former brothers and their Legions.[Needs Citation]
Agonizing over the betrayal of his most beloved son, the Emperor ordered the deployment of seven full Space Marine Legions against him. Their orders were to take Horus and the Primarchs allied with him into custody and bring them back to Terra to explain their actions. Unbeknownst to the Emperor, four of the Primarchs and their Legions chosen for this task had already turned against him, forming a "fifth column" which would strike against the loyalists at the most decisive moment.[Needs Citation]
The initial naval operations seemed to go well for the loyalists. The Imperial Navy gained orbit over Isstvan V and the Legions proceeded with their planetary deployment. Under the overall command of Ferrus Manus, three whole Legions took part in the first wave of landings; the Salamanders lead by Vulkan, the Raven Guard under Corax, and Manus's own Iron Hands. Horus had foreknowledge of the location of the loyalist drop site and his forces mauled the Legions during their landings, keeping them pinned down and unable to advance.[Needs Citation]
Ferrus Manus engaged Fulgrim in personal combat, only to die at his hands while the Emperor's Children butchered the Iron Hands. The loyalists retreated towards the apparent safety of their brothers in the second wave, hoping to gain reinforcement; what happened next took them completely by surprise. The four Legions of the second wave - The Night Lords of Konrad Curze, the Iron Warriors of Perturabo, the Word Bearers of Lorgar, and the Alpha Legion of Alpharius - already seduced to the cause of Horus, opened fire on their unsuspecting brothers, slaughtering them wholesale. This orgy of carnage would later become widely known as the Istvaan V Drop Site Massacre. A phrase attributed to the Warmaster himself can easily summarise the entire battle: "When the traitor's hand strikes, it strikes with the strength of a Legion." After the battle, Fulgrim presented the head of Ferrus Manus to Horus as a trophy.
The Rebellion Spreads
During the developments at Prospero, Horus's rebellion would be further strengthened by Magnus the Red and his Legion, the Thousand Sons, now servants of Tzeentch. In addition, the Schism of Mars, the civil war of the Adeptus Mechanicus, had ended in the victory of the Warmaster's allies, the Dark Mechanicum. With nine Legions and much of the Adeptus Mechanicus behind him, Horus quickly struck towards Terra after gaining the powers of the Emperor after the Battle of Molech. To occupy the bulk of remaining loyalist forces, he commanded the Alpha Legion to bog down the Space Wolves at the Battle of the Alaxxes Nebula and White Scars in the Chondax Campaign while having the Night Lords rampage throughout the Imperium to draw the attention of the Dark Angels in the Thramas Crusade. Thus, with the Ultramarines still reeling from their battle with the Word Bearers at the Battle of Calth, only the Imperial Fists, Blood Angels, and White Scars (who managed to escape the Alpha Legion and return to Terra) were in any position to defend the capital world in force[2e].
The Traitor Marines laid waste to their former allies' holdings along the way to Terra. Despite the traitor defeat on Calth, Erebus was successful in creating the Ruinstorm which threw the Astronomican into disarray and rendered navigation and communication difficult. As a result, Roboute Guilliman feared the Imperium lost and created a second empire, Imperium Secundus, as a contingency.
After years of bitter fighting, Horus and his forces finally arrived at Terra, capital of humanity. For several years previous, traitors had been wresting control of the Sol System from the Imperial Fists in the Solar War. During these battles, the Alpha Legion struck at Pluto and Alpharius himself was seemingly killed by Rogal Dorn.
Nonetheless, eventually only Terra itself stood. Once within range of Terra, Horus and his forces destroyed Luna's naval bases and within thirty days had destroyed the Terran system's defences. Terra was bombarded and devastated.The corrupted Marines eventually landed on Terra, experiencing heavy resistance from the defenders. Among these loyalists were Blood Angels, Imperial Fists and White Scars. The loyalists were outnumbered and the battle for Terra turned into a siege of the Imperial Palace. By the fifty-fifth day the rebels had reached the walls of the Inner Palace. Horus, who had remained in orbit aboard his battle barge, was at that point warned that the rest of the loyalist Legions were returning to Terra and would arrive in hours. The Ultramarines were pushing their way to Terra, along with the Space Wolves and the Dark Angels. If this were to happen, Horus's advantage in numbers would be diminished. He let down the force field protecting his battle barge to lure the Emperor in a final battle that would decide the war.[Needs Citation]
The Emperor saw this opportunity and teleported to the Warmaster's battle barge with two of his Primarchs, Terminator-armoured marines of their Legions, and a number of Custodes. The Emperor's forces were scattered through the ship upon arrival and forced to battle their way to find each other. Sanguinius found Horus first. Horus was at the height of his powers, augmented with the blessings of all four Chaos Gods and the god-like powers he had acquired during the Battle of Molech, and Sanguinius was slain. Horus stood over the Primarch's body as the Emperor found him. After a long and gruelling battle, the Emperor was successful in defeating Horus, but he himself was mortally wounded. The Emperor survived long enough to be transferred to the Golden Throne - a strange mechanism that would allow him to survive forever in a state of undeath.[Needs Citation]
The Emperor's final command began the Great Scouring. All forces loyal to Horus were hounded into the Eye of Terror and planets such as Davin and Isstvan V were sterilized. All records and the remaining homeworlds of the traitor legions were destroyed. Ezekyle Abaddon, assuming the epithet "the Despoiler," would be the closest the traitor legions would have to a unified leader and he would lead a number of Black Crusades into the Imperium in the centuries to come.[Needs Citation]
- Timeline of the Horus Heresy
- Major Battles of the Horus Heresy
- List of Horus Heresy Characters
- Schism of Mars
- Horus Heresy Series
- The Horus Heresy (Game)
- Horus Heresy Collectible Card Game
- The Horus Heresy: Betrayal at Calth
- Horus Heresy (Board Game)
- List of Anti-Imperial Rebellions
- 1: Realm of Chaos: Slaves to Darkness (1988), pg. 243
- 2: Horus Heresy (Artbook Series)
- 3: The First Heretic (Novel) by Aaron Dembski-Bowden, Chapters 13-14
- 4: Prince of Crows (Novella)[Needs Citation]
- 5: The Outcast Dead (Novel) by Graham McNeill, [Needs Citation]
- 6: The Unremembered Empire[Needs Citation]
- 7: The Horus Heresy Book Two - Massacre, pg. 19
- 8: Black Library (Source notes a seven year gap between the Isstvan Campaign and Siege of Terra)
- 9: False Gods (Novel) Chapter 14
- 10: Vulkan Lives (Novel)
- 11: Deliverance Lost (Novel) Chapter 6
- 12: Games Workshop Golden Demon presentation 2014 (Image here)
- 13: Praetorian of Dorn (Novel)
- Horus Heresy (Artbook Series), pg. 101