"Hydra Dominatus!" or "For the Emperor!" (Believed to be used as a mockery; but may actually indicate the Legion's true loyalty)
First Founding (30th Millennium)
Blue, Silver and Green
- "The Imperium is riddled with corruption and hatred. We have made sure of it."
- — Anonymous Alpha Legion Chaos Space Marine
The Alpha Legion is the Chaos Space Marine Traitor Legion about whom the least is known. The Alpha Legion was once the XX Legion of Astartes created during the First Founding by the Emperor of Mankind to carry out his Great Crusade to reunite all of humanity in a new Golden Age under his rule. They are experts in infiltration and their armies contain many Chaos Cultists in addition to regular Chaos Space Marines. The Alpha Legion's Primarch was named Alpharius, who was actually one of the identical twin Primarchs Alpharius Omegon, two brilliant and secretive sons of the Emperor, one of whom was reportedly later killed after end of the Horus Heresy by Roboute Guilliman, the Primarch of the Ultramarines. Despite its seeming allegiance to Chaos, a closer scrutiny of the Alpha Legion's known history indicates that their seeming service to Chaos Undivided might actually be the greatest deception they have played upon the Imperium.
Alpharius and Omegon were the final Primarchs to be found, just prior to the end of the Great Crusade and the beginning of the Horus Heresy. Horus, Primarch of the Sons of Horus, followed an escaping group of pirate spacecraft into an asteroid field where they were set upon by multiple smaller craft. Despite being overpowered and outnumbered, Horus' opponents managed to flank him at almost every turn and eventually his own command craft was boarded. A group of five men, the fifth much larger than the rest, burst onto Horus' bridge, and Horus promptly slew four of them. The fifth managed to dodge Horus' shot and the two nearly came to blows before Horus recognised that the enemy warrior could only be a fellow Primarch.
Alpharius, unlike the other Primarchs, was introduced to the Emperor in only a casual way before being given command of the XX Legion, ironically dubbed the Alpha Legion (whether this was out of irony for being the last Space Marine Legion created or was based on Alpharius' name is not known). Horus took Alpharius under his wing, and even gave overall command authority to Alpharius in later campaigns. In a bizarre turn, Alpharius refused to reveal the location of his homeworld, normally the site of much of an Astartes Legion's recruitment, to the budding Imperium. It is unknown whether Alpharius even had a homeworld or where he matured following his removal through the Warp from the Emperor's gene-labs on Terra.
As the last Astartes Legion created during the First Founding, work on the XX Legion was begun only a few decades before the discovery of their Primarch, Alpharius Omegon. As a result, when Alpharius took command of the Legion, it was young, zealous and completely committed to embracing the Primarch's command and combat philosophy.
Alpharius and Omegon shared the same physical appearance and only together served as the joint Primarch of the Alpha Legion. It is also stated that the Emperor knew Alpharius Omegon's secret; but whether the creation of twin Primarchs was intentional or not remains a mystery. The two Primarchs supposedly share one soul, and Omegon acted as Alpharius' second-in-command of the Legion. The existence of the two Primarchs of the Alpha Legion was known only to the members of the Legion itself, and was a well-kept secret even from the other Legions.
Alpharius believed that secrecy, adaptability and fluidity brought military success, and taught his Legion to apply all such military techniques to both their training and their operations. The Legion's victories in the Great Crusade all feature some form of subterfuge, misdirection or rapid, unexpected movement. Such victories required great skill and dedication to achieve, and the Alpha Legion quickly became an insular and proud military organization. It was this martial pride and unusual philosophy that led to a number of clashes and fights with members of the other Space Marine Legions, particularly against their rivals the Imperial Fists on several instances.
After Alpharius' disagreements with Roboute Guilliman over the dishonourable ways of the Alpha Legion's chosen methods of warfare, the Alpha Legion threw themselves even further into their preferred method of operations, largely cutting themselves off from standard Imperial military practices and orchestrating greater and greater victorious examples of their approach to the Great Crusade, even when more conventional attacks would have been more efficient. The most notorious example of this took place on the world of Tesstra Prime, where the Alpha Legion, instead of taking the opportunity to capture the planetary capital city and thus force the world's surrender, allowed the enemy to dig in and defend it so that they could then expertly take the defending forces apart in a number of different ways. After a week of suffering seemingly random mishaps and deadly sabotage as well as brutal ambushes, the defenders were forced to capitulate, having taken 90% casualties. When asked why the Legion had not taken the simpler strategy, Alpharius is reported to have replied that they avoided it as "it would have been too easy". This campaign brought Alpharius censure from almost all of his brother Primarchs; Guilliman in particular raged at Alpharius' conduct of the war, labeling the drawn-out operation as "a waste of the Emperor's bolt shells". Only the Warmaster Horus, always impressed by Alpharius and his work, praised the Alpha Legion's skill.
With such examples existing in the Imperial records, it is perhaps easy to see why the Alpha Legion sided with Horus when the Warmaster made his pact with Chaos and rebelled against the Emperor; their martial pride and Alpharius' avoidance of all his Primarch brothers apart from Horus seemingly the catalysts for their downfall. Yet, the Alpha Legion's turn to Chaos was, oddly, something they chose for the sake of the Imperium. While undertaking a war of Imperial Compliance on the planet of Nurth some two standard years before the outbreak of the Horus Heresy, the twin Primarchs were approached by a man named John Grammaticus, an agent of an alien organisation known as the Cabal. The Cabal revealed to Alpharius Omegon, as well as two other men, Peto Soneka and a psyker by the name of Shere, the outcome of Horus being named Imperial Warmaster of the Great Crusade -- the onset of the terrible civil war called the Horus Heresy. They then presented two psychically foreseen possibilities to the twin Primarchs: If the Emperor won the impending civil war, the Imperium of Man would slowly decay over the next ten to twenty millennia until it and trillions of souls were ultimately consumed by Chaos. If Horus won the war, however, after "two to three generations" Horus would be wracked with guilt for slaying his father the Emperor and would ultimately obliterate all Chaos-tainted factions in the galaxy and humanity itself in constant warfare. Humanity would be destroyed in the process, but the Emperor's greatest foes, the Chaos Gods, would be all but eliminated because so much of their power derived from the inherent psychic flaws of humanity itself.
At this point, both Primarchs staggered back and screamed at the vision, “The Alpha Legion has always, always, been for the Emperor,” Alpharius stated. The Primarchs ultimately chose to follow Horus in their belief that the ultimate destruction of Chaos was the choice the Emperor himself would have made, yet their loyalties remained with the Emperor even as they swore their souls to Chaos Undivided.
The Cabal may have been sincere in its desire to prevent the terrible onset of the stagnation and constant warfare for the Imperium of Man that the Horus Heresy would initiate or it may have intentionally mislead the Primarch, as the support of a Loyalist Alpha Legion might have changed the course of the campaign in ways that would have precluded Horus from reaching the Emperor and mortally wounding him. Instead, by supporting Horus, the Alpha Legion actually implemented the future for humanity they had sought to prevent. It is unclear whether the Cabal misunderstood their psychic visions, thus acting in such a way that they created a self-fulfilling prophecy, or whether they were actually agents of Chaos or some other faction with an interest in attempting to subvert an otherwise loyal Legion.
The Alpha Legion's battle cry of "For the Emperor!", when viewed in this light, is not the mocking insult of a Traitor Legion it was once thought to be. Rather, it is a testament to the Legion's devotion that they have stayed true to their cause for so long. It is thought that the Alpha Legion's true goal is to release the Emperor from his "prison" of the Golden Throne so the revelation made to them by the Cabal is fulfilled.
The Horus Heresy
After the virus-bombing of Istvaan III, the presumed Loyalist Alpha Legion was one of the Space Marine Legions sent by the Emperor to destroy Horus and the Traitor Legions at their base on Istvaan V. Assigned to the second wave, the Legion instead turned on the Loyalist first wave during what became known as the Drop Site Massacre. It is thought by many that much of the Traitors' strategy on Istvaan V was planned by Alpharius and the Alpha Legion.
In the ensuing slaughter, the Loyalist Iron Hands, Salamanders and the Raven Guard were decimated. Ferrus Manus was killed by the traitorous Fulgrim of the Emperor's Children, Vulkan went missing and Corax was severely wounded. For over three months, the remnants of the Raven Guard were pursued by the ravenous World Eaters, who were intent on completely annihilating the Loyalist Legion. Their Legion hard-pressed by the Traitors, Corax and the remnants of his Legion prepared to sell their lives dearly. But their fortunes quickly changed with the arrival of a rescue force of Raven Guard Thunderhawks and Stormbirds to retrieve the remaining survivors.
By this time, it had been well-established that the Alpha Legion was well-known for their subterfuge and ability to blend-in with any environment, mimicking those that they infiltrated to gather intelligence, perform sabotage, or plant disinformation. They have also been known to use more drastic measures, such as those employed during the actions on Istvaan V during the opening days of the Horus Heresy. The Alpha Legion played a pivotal role in the infiltration of the Raven Guard to gather vital intelligence on the Imperium's defences within the Sol Sector as well as the Imperial Palace on Terra.
Part of the bargain agreed with the Warmaster was for the Alpha Legion to spread disinformation ahead of the events that had occurred in the Istvaan System, whilst seeking new forces for Horus’s cause. It was better that Horus’s version of events was heard first, casting doubt on the rumours and propaganda that soon followed in the wake of these horrific events. It was a mission Alpharius and Omegon were well-prepared to undertake. On many other worlds, Alpha Legion operatives and legionnaires sowed discord amongst the Emperor’s followers, stoking thoughts of rebellion in those who had been forced into compliance by the Legiones Astartes.
During the remainder of the Heresy, the Alpha Legion split off from the main body of Horus' forces early and did not attack Terra with the majority of the Traitor Legions, instead embarking upon a series of delaying actions in an attempt to hold potential Imperial reinforcements for the defence of Terra in place. They also engaged in smaller actions, defeating a White Scars force on Tallarn and a Space Wolves unit at Yarant. Despite their contributions, however, Horus was ultimately defeated by the Emperor aboard his battle barge at the end of the Siege of the Imperial Palace on Terra.
In the aftermath of the Horus Heresy, the Alpha Legion did not retreat to the Eye of Terror like the other Traitor Legions; instead the XX Legion moved on into the galactic East, following new objectives of their own devising. As such, the Legion was not pursued into the Eye of Terror as so many of their fellow Traitors were, but became embroiled in a series of bitter confrontations with the Ultramarines, who themselves had been engaged in that region when Horus had assaulted Terra.
On the world of Eskrador, the Alpha Legion was assaulted by Ultramarines forces. Alpharius was reportedly happy with such a development, as it allowed him to demonstrate the superiority of his flexible, multitudinous and unexpected military strategies over the notoriously precise, methodical and perhaps even tactically moribund Ultramarines. The Ultramarines' Primarch Roboute Guilliman would prove himself the better strategist when he accurately predicted that the Alpha Legion would believe they could foresee the tactics he would utilise in the coming battle. For perhaps the only time in his life, Guiliman acted contrary to his own firmly-held military doctrines, and it was Alpharius who walked into a trap.
Accounts vary as to why the Ultramarines and the Alpha Legion fought one another at Eskrador. Some say Alpharius wanted to prove the superiority of his tactics, whilst Guilliman wanted revenge on one of the Traitor Legions for the death of the primarchs' beloved Emperor, and so tracked down the traitorous Alpha Legion in the Eskrador System. Alpharius' Legion was the first to arrive and was able to choose their battleground and set the perfect trap for the upstart Ultramarines.
With access to all the records of the tactics used by Guilliman during the Great Crusade, Alpharius used this information to take full advantage of the Ultramarines' standard operating procedures. At first the battle was a stalemate between the two evenly matched Legions, but Guilliman chose nightfall to do something unexpected, leading a large portion of his forces with no lines of support or supply deep into the mountains where they deployed by Thunderhawk, Drop Pod, and teleporter in the midst of the Alpha Legion. The Ultramarines quickly took advantage of the situation and soon had the Alpha Legion's command centre in disarray. Hard-pressed by the vengeful Loyalist force, which outnumbered them five to one, the Alpha Legion was unable to fall back up the mountain valley. They were hampered by the terrain and were forced to make a last stand at the head of the valley. Alpharius himself led a furious counterattack against the Ultramarines and was slain in single combat by Roboute Guilliman. None knew that the Alpha Legion still had another Primarch, who soon adopted the role of his slain brother. This final deception would present the Imperium with an unexpected and very nasty surprise time and time again.
Having burned the Traitor Primarch's body on a great pyre, Guilliman led his Legion against the remnants of the Alpha Legion on Eskrador, only to discover that far from collapsing, the XX Legion was mounting a series of cunning and often devastating counter-strikes. The Alpha Legion responded not by breaking and fleeing as Guilliman had expected after the death of their Primarch, but by turning on the pursuing Ultramarines detachment and harrying them so mercilessly that by the time they had returned to the main body of the Ultramarines force their casualties were almost total. After days of bitter fighting, Guiliman gave up hope of an honourable victory and departed Eskrador, ordering a massive orbital bombardment to finish the XX Legion's survivors off. Some Imperial savants have claimed that the entire battle was some grand ploy unleashed by the Alpha Legion, though to what end none can say. Certainly, the Alpha Legion fought in the manner of the mythical beast that adorns their armour -- the hydra -- for each time one head was cut off, another moved in to replace it.
Following the Battle of Eskrador, the Alpha Legion fractured in order to hide from the Imperium. Small, autonomous warbands were left in Imperial space where they set up secret bases in asteroid fields, on Space Hulks and on barren, unpopulated worlds. These units launched frequent attacks against Imperial military targets that had already been weakened by the Heresy and even today these warbands still pose a threat to Imperial starships, settlements and garrisons. The Alpha Legion's warbands also coordinate the spread and actions of Chaos Cults throughout the galaxy in order to instigate massive planetary revolts against Imperial rule. These insurrections are often used to lure Imperial forces away from more strategic worlds the Alpha Legion proper wants to attack, paving the way for large-scale assaults of Chaos Space Marines from the Eye of Terror.
Unlike the other Traitor Legions, most of the Alpha Legion does not reside in the Warp, but rather roams the galaxy as scattered warbands of warriors, each of which is trained to act independently of the others in pursuit of their greater cause. In this way the Alpha Legion was by and large the only Traitor Legion not to succumb to the mutations of Chaos, an outcome that may also have been dictated by their continued secret loyalty to the Emperor of Mankind. The Alpha Legion's role in spreading heretical Chaos Cults across the Imperium has earned them the loathing of the Inquisition, whose Ordo Malleus and Ordo Hereticus have devoted considerable resources to finding and destroying their secret bases. The Alpha Legion has been declared wiped out by the High Lords of Terra no less than three times, in the 31st Millennium, the 32nd Millennium and the 39th Millennium. These claims have always been disproved by the next Alpha Legion-inspired plot or rebellion that breaks out somewhere in the Imperium and proves that the hydra still has more heads to slay.
- Compliance of Five-Twenty-Nine (Unknown Date.M30) - This was an Imperial Compliance action carried out by the Alpha Legion against an adversary of unknown origin upon the world designated Five-Twenty-Nine.
- Compliance of the Ferinus Worlds (Unknown Date.M30) - This was an Imperial Compliance action carried out jointly by the Alpha Legion and an Imperial Army sentry force comprised of the Geno Seven-Sixty Spartocid. The Seven-Sixty were a well-drilled regiment and did not spook easily. They played an instrumental role during the Compliance of the Ferinus Worlds.
- Compliance of Thorium Abominiplex (Unknown Date.M30) – This an Imperial Compliance action that was carried out jointly by both the Alpha Legion and Death Guard Legions against an unrecorded adversary.
- Conquest of Tesstra Prime (Unknown Date.M31) - During the Great Crusade, the Alpha Legion was given the honour of subjugating the non-Compliant world of Testra Prime, whose population was violently resistant to the idea of Imperial rule. Through the tactical brilliance and strategic genius of Alpharius Omegon, the Legion employed their well-known deceptive tactics and were able to overcome an opposition that outnumbered them a hundred to one. Alpharius Omegon's conduct invited censure from many quarters, especially from Primarch Roboute Guilliman of the Ultramarines Legion, who declared the Alpha Legion's tactics dishonourable and unworthy of Astartes. Horus was the only Primarch who openly praised his brother Primarch and the way in which his Legion had conducted a truly masterful campaign.
- Kayvas Persecution (Unknown Date.M31) – 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 Greenskin xenos soon began to strike out at nearby Imperial star systems and newly Compliant daughter colonies, and it was the duty of the Space Marine Legions to reinforce the lesson of Ullanor again. 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 XX 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, but like animals backed into a corner they fought harder than they ever had before. The 88th Expeditionary Fleet took their warships into the Kayvas Belt and vanished from the sensors of the IX Legion's fleet, leaving the Blood Angels flotilla at the edge of the system to wait. Soon it became clear that the mission Alpharius had been so eager to secure support for was little more than picket duty. First one at a time, then in squadrons and finally in fleets, the Orks began to flee from the Kayvas System. Each time they bolted for open space beyond the mass shadow of the supergiant sun and its asteroid belt, the Blood Angels were waiting for them. Imperial starships and Ork cruisers engaged in deadly games of cat-and-mouse that lasted for weeks on end, threading in and out of the dense dust clouds at the periphery of the star system, mercilessly hunting each other. Mighty vessels clashed again and again, but months of protracted ship-to-ship engagements and naval warfare made the Sons of Baal restless. They had been bred for battles where they could face their foes, not ranged conflicts conducted over huge spans of empty vacuum. However, the chance to fight blade-to-blade did come. The behaviour patterns of the Ork crews began to change. They eschewed what little animal cunning they had and made mistakes. Instead of showing the brutish slyness they were known for, the xenos exhibited conduct that more closely resembled panic. They would take chances, running the gauntlet of the Blood Angels' blockade when the odds were stacked against them. It was almost as if there were something at their backs that they feared far more than the guns of Sanguinius’ Legion. No one within the IX Legion knew what the Alpha Legion had done to make the Orks run. All that was certain was that the Alpha Legion had gone dark, only rising to send regular communiqués out to the Blood Angels' blockade fleet that contained little more than a message to "maintain the line." Finally, Sanguinius tired of Alpharius’ evasive manner and sent a frigate in past the outer marker, in defiance of the rules of engagement the two Legions had agreed upon. When the frigate returned weeks later, the crew reported that they had come across no signs of their allies, only the wrecks of Ork vessels and the bodies of dead aliens. The Alpha Legion's 88th Expeditionary Fleet comprised hundreds of warships, and yet no trace of them was sighted. The tempo of the Kayvas campaign had finally reached a terminal pitch. The final remnants of the Ork forces took flight from the belt in a disordered exodus, and perished in the flashes of Lance cannons and torpedo barrages as they crossed the sentry line. At last, the Alpha Legion's starships appeared at the very edge of scanning range, apparently moving in a wall, herding the enemy towards the fringes of the system. The Alpha Legion stated they had fully exterminated the alien infestation in the Kayvas Belt, and were grateful to the Blood Angels for their co-operation. The blockade was finally over, and with the death of the final monolithic Ork wreck at the hands of the Blood Angels fleet, the campaign came to a successful conclusion, though relations between the IX and XX Legions remained somewhat strained.
- Assault on Nurth (Unknown Date.M31) - The Desert World of Nurth was discovered during the Great Crusade by the 670th Expeditionary Fleet under the command of Lord Commander Teng Namitjira. Nurth was a lost human colony world. The population refused to accept the light of the Imperial Truth and opted not to join the Imperium of Man, resulting in a drawn-out, protracted compliance campaign that would eventually result in the death of the entire world. The Primarch Alpharius and a force from his XX Legion, the Alpha Legion, fought alongside the 670th Expedition during the tragic campaign to bring the world of Nurth to Imperial Compliance, but never became an official part of the 670th Expedition's order of battle. Lord Commander Namitjira remained in formal command during the operation, though of course he deferred to the Primarch's orders. When first contacted by the Imperium, Nurth was a primitive, pre-industrial Desert World with geographic features fairly typical for such an arid environment. An exception to this was the harbour of Mon Lo, in the city of the same name. The harbour, while appearing perfectly natural to the ordinary onlooker, was actually an entirely artificial construction, having been created by the xenos organisation known as the Cabal some 11,826 Terran years before the arrival of Imperial forces on the world. Before natural environmental changes had filled the harbour of Mon Lo with water, the bay had served as a giant landing pad or "waystation" for the Cabal's massive primary starship. As such, a detailed orbital scan of Mon Lo revealed features similar to that found on other worlds where Cabal waystations were built and the Cabal's mobile headquarters had come to rest for a time. Another location that featured unusual terrain was the town of Tel Khat, also known as Visages. The plain surrounding the town was littered with old, weathered sculptures of human heads, made from diorite and ranging in size from a pebble to a boulder. For unknown reasons, the ground of Nurth was coloured a striking combination of red and orange and the sky an unusually vibrant blue. This, combined with the brightness of the desert environment, meant that glare-protection was essential equipment for all military forces operating on the planet, so as to avoid disorientation and eventual eye damage. Nurth was eventually destroyed by the Nurthene themselves, as, on the verge of losing the war against the Imperial forces, the Echvehnurth, the Chaos-corrupted Nurthene military forces, activated a Chaotic weapon known as a Black Cube, an ancient weapon of planetary destruction created eons before by the first intelligent races of the galaxy. This weapon, through unknown means, transformed the climate of the planet, turning the air into noxious vapours utterly inimical to any form of life, and generating winds so strong that they scoured soil from the bedrock and raised the temperature to the point where the ocean boiled. In a matter of days, the process was complete, leaving Nurth a lifeless Dead World.
- Drop Site Massacre of Istvaan V (006.M31) - Noted as one of the most devastating defeats in the history of the Adeptus Astartes, the Drop Site Massacre of Istvaan V saw the Raven Guard and Salamanders Legions nearly annihilated as effective fighting forces and only the quick thinking and initiative of the Salamanders allowed a bare few Space Marines of these two Legions to escape that dreadful day. In response to the treachery of the Warmaster Horus and his betrayal of the Loyalist Astartes in the Sons of Horus, Emperor's Children, World Eaters and Death Guard Legions at Istvaan III, the Primarch of the Imperial Fists Legion, Rogal Dorn, on the direction of the Emperor who had learned of Horus' actions from the Loyalist survivors aboard the Eisenstein, ordered 7 Loyalist Space Marine Legions to Horus' base on the world of Istvaan V to challenge the Traitors. They would attack in two waves and fall under the supreme command of the Iron Hands' Primarch Ferrus Manus. The Legions comprising the first wave were the Raven Guard, Iron Hands and Salamanders. The Legions comprising the second wave were the Alpha Legion, Night Lords, Iron Warriors, and a large contingent of Word Bearers that their Primarch Lorgar had stationed in the star system. Unknown to Dorn and Ferrus Manus, the Night Lords, Alpha Legion, Iron Warriors and Word Bearers had all turned from their service to the Emperor and secretly pledged their loyalty to Horus, and been instructed to keep their new allegiance to Chaos a secret. The Iron Hands, Salamanders and Raven Guard were deployed in the first wave of the assault. After they secured the drop site, they were to have been followed by the arrival of the other four Legions. The first wave secured the drop site, known as the Urgall Depression, though at a heavy cost. Horus ordered his front line troops to fall back in a feint, tempting Ferrus Manus to overstretch his already thin lines. Against the advice of Corax and Vulkan, Manus led his Veterans against the fleeing Traitor Marines unsupported. Manus then brought his brother Fulgrim to combat. As the two Primarchs drew their weapons, the Raven Guard and Salamanders fell back to regroup and allow the second wave's Legions to advance and earn glory. However, as they returned they were mowed down by the four Traitor Legions that had landed to supposedly support them, thus revealing their new allegiance to Chaos. At the same time the apparent rout of the Sons of Horus, the World Eaters, Death Guard and Emperor's Children suddenly halted and the Traitors pressed their attack. As Horus pressed the counterattack he managed to sandwich the Loyalists between the two Traitor forces, killing most of them. Meanwhile, the Iron Hands were cut off and slaughtered to a man -- the Veteran Morlocks Terminators cut down and the Primarch Ferrus Manus beheaded by Fulgrim. The Salamanders and Raven Guard could do nothing to help the Iron Hands, and were forced to make a costly break-out with precious few of their forces. Those Thunderhawk and Stormbird gunships that lifted off and escaped Istvaan V were far fewer than those that had landed. Corax, the Primarch of the Raven Guard, was badly wounded and Vulkan's fate was unknown for some time. The remainder of the Iron Hands Legion arrived to find their Veterans and Primarch dead while the Salamanders and Raven Guard had been reduced to a fraction of their full strength, with both Legions nearly wiped out.
- Raven Guard Infiltration (006.M31) - Shortly after the Drop Site Massacre on Istvaan V early in the Horus Heresy, and unbeknownst to Loyalists and Traitors alike, the Alpha Legion managed to infiltrate the remnants of the Raven Guard Legion, surgically altering Alpha operatives to resemble dead Raven Guard Space Marines and then inserting them into the ranks of the XIX Legion during the chaos of the Drop Site Massacre. Acting on information received from the alien organisation known as the Cabal, Alpharius Omegon believed that the XIX Legion was going to eventually receive an extremely valuable, top-secret asset from the Emperor that would prove to be of immense value to the Traitors' cause if it could be secured. In an operation personally overseen by Omegon, the Alpha Legion managed to appropriate the asset, which turned out to be a sample of pure Primarch gene-stock and related information on its genetic manipulation that the Primarch Corax had recovered from the Emperor's gene-laboratories beneath the Himalazian Mountains in the bowels of the Imperial Palace. Playing their typical game of deception and intrigue against all sides, Alpharius Omegon mislead Horus by surrendering tainted information about the pure Primarch gene-stock to the Traitors' chief geneticist, the Emperor's Children's Chief Apothecary Fabius Bile. However, Horus knew that the Alpha Legion might have infiltrated any Legion, and had ordered the Alpha Legion to be put under surveillance by other Traitor forces to prevent any double-dealing. Alpharius Omegon also mislead the Cabal, by not destroying the pure Primarch gene-stock as they had promised to damage the Loyalists' war effort, keeping it for their own benefit. However, the pure gene-stock had been infected by a daemonic virus that had been intended to make it worthless to the Raven Guard. The Alpha Legion had been assured by the Tech-adepts of the Dark Mechanicus that this daemonic taint could be removed once the Primarch gene-stock was in the hands of the Traitors, but whether this assertion proved to be correct remains unknown. A second, major objective of the Raven Guard infiltration by the Alpha Legion was the destruction of the Raven Guard's remaining stocks of gene-seed, thereby eliminating any chance that the XIX Legion could be rebuilt after the massacre on Istvaan V. However the Alpha Legion failed in this objective due to the heroism of the Astartes of the Raven Guard, and the XIX Legion was eventually able to reconstitute itself and play a crucial role in the future history of the Imperium.
- The Tallarn and Yarant Campaigns (Unknown Date.M31) - During the Horus Heresy the Alpha Legion went out of its way to prove itself as capable as its Loyalist Space Marines counterparts. The XX Legion inflicted stinging defeats on the Loyalist White Scars at Tallarn, a company of the Space Wolves at Yarant, and units of the other Loyalist Legions at dozens of smaller outposts.
- Battle of Eskrador (Unknown Date.M31) - After the death of Horus at the end of the Horus Heresy during the Great Scouring, the Alpha Legion and the Ultramarines Legion met in battle on the world of Eskrador, where Roboute Guilliman faced his hated brother Primarch in bitterly contested close combat. Both struck one another in an instant, each power sword making a single stroke. For a second the two Primarchs stood facing one another, than Alpharius slumped to the ground. Exalted by their Primarch's victory the Ultramarines renewed their attack and cut down every last Alpha Legionnaire. But their exaltation was short lived, as over the next few days the Ultramarines were harried from all sides by the Eskandor natives as well as remnants of Alpha Legionnaires hiding throughout the mountains. After another week of futile combat against their shadowy opponents, Guilliman ordered his Ultramarines to evacuate the planet's surface. He then used his Legion's ships to bombard the traitors from orbit. Despite Guilliman's protests that he had no wish to fight such dishonourable foes, it seems hard to dispute the fact that the Ultramarines were soundly beaten by the Alpha Legion at every turn, despite the loss of Alpharius.
- Gothic War (12th Black Crusade) (139.M41 - 160.M41) - This was a vast military campaign against the Imperium of Man launched by Abaddon the Despoiler. This conflict consisted of hundreds of planetary invasions and naval battles and only ended when Abaddon was forced to retreat to the Immaterium with the arrival of Imperial reinforcements. The only known battle the Alpha Legion took part in was the Lethe Ambush, though undoubtedly the Legion were working behind the scenes manipulating the outcomes of battles, using secret spy networks and fomenting rebellion to assail their enemies from as many different directions as possible in carefully orchestrated attacks.
- Daethryu Plague (255.M41) - The Agri-world of Daethryu Prime was suddenly plagued by a species of locusts not usually found anywhere in the sector. Thriving in the planet's warm climate the locusts multiplied exponentially, decimating food crops and causing a planetwide famine. The population had a surge of anger and unrest which they directed at the planet's ruling authorities. Within a week's time, riots broke out in every major population center and much of the local military mutinied. A Mordian Iron Guard regiment was dispatched to quell the riots but was ambushed and summarily destroyed as they disembarked from their transports by a force of hidden Chaos Space Marines. The complete loss of food exports caused major supply problems in the subsector for years, resulting in further unrest on other worlds. This hindered Imperial forces during subsequent Chaos incursions into the Segmentum Pacificus. It seems certain the Alpha Legion orchestrated much of the events that occurred in the sector, more than likely being involved at some level.
- Tartarus Campaign (Unknown Date.M41) - The 3rd Company of the Blood Ravens Chapter of Space Marines and its task force under the command of Captain Gabriel Angelos were sent to the aid of the Imperial forces on the besieged Civilised World of Tartarus, which had been invaded by an Ork WAAAGH!. Over the course of the campaign the Blood Ravens uncovered the planet's dark history, locating numerous sites of Chaos power and relics of the Eldar, left behind to aid future generations in continuing to battle the forces of Chaos trapped on the planet. Over the course of the fighting most of the population that was not evacuated either fell to Chaos or was slain by the Orks and very few civilians escaped from Tartarus. In truth, the Ork invasion had been only a diversion. A warband of Chaos Space Marines from the Alpha Legion, led by the Chaos Lord Baal and the Chaos Sorcerer Sindri Myr had used the cover of the Ork WAAAGH! to make planetfall undetected on the world and begin their own operations in pursuit of an ancient and very powerful Chaotic artefact present on the world known as the Maledictum. Gabriel Angelos, whose own intuition indicated that there was more to the situation on Tartarus than met the eye, disregarded the warnings of the Ordo Malleus Inquisitor Mordecai Toth and continued to hunt down the hidden forces on the planet. Finally Gabriel discovered that a force of Eldar from the Biel-Tan Craftworld had come to reseal a powerful Daemon in the Chaotic artefact known as the Maledictum that had been hidden on the planet, underneath its capital city. However the Blood Ravens broke the back of the Eldar forces, slaying the Avatar of Khaine and killing many of the Eldar warriors. Despite their intervention Sindri managed to steal the Maledictum and its key from underneath the Imperial and Xenos forces. Perhaps the most regrettable event of the fighting on Tartarus was not the many Battle-Brothers lost, but the treachery of Librarian Isador Akios, who had been an initiate with Gabriel. He became corrupted by the power of the Maledictum, and it was he who handed it over to Sindri, despite believing himself to be in control, he had been manipulated by the Chaos Sorcerer from the beginning. His treachery could not be forgiven and Isador proved the weaker when he was faced in personal combat by Gabriel Angelos. At the conclusion of the Campaign, Gabriel shattered the Maledictum with a Daemonhammer forged from a shard of the Wailing Doom, the blade of the Biel Tan Avatar of Khaine. This only released the Daemon, however, due to the sheer amounts of bloodshed on the planet which served as a sacrifice that empowered the daemon's awakening. When the Daemon was released it hinted at a connection between itself and Inquisitor Toth. It would appear that the Inquisitor was not as pure as he seemed to be. However Gabriel was unable to pursue the matter further, having to escape the planet with the wounded and the single recruit taken from the planet, Storm Trooper Sergeant Ckrius. The young Guardsmen had been taken under the wing of Terminator Sergeant Tanthius and despite being badly wounded in the fighting was taken aboard the Litany of Fury, where he began the long and painful process of becoming a Space Marine. On Tartarus the Scout Sergeant Corallis suffered grevious injuries at the hands of the Eldar's Warp Spiders, however he survived and returned to service with the aid of numerous bionic replacements.
- Ambush at Kruger Ridge (Unknown Date.M41) - Chapter Master Quesiah Ichabod of the Excoriators Space Marine Chapter had come to the world of Ignis Prime to inspect the Excoriators’ mountaintop garrison of Kruger Ridge. He found a slaughterhouse rather than a Chapterhouse, and a waiting ambush in the form of an attack by the Chaos Space Marines of the Alpha Legion. It was there, barricaded in the oratorium, that Chapter Scourge Zachariah Kersh had fallen to Dorn's Darkness, failing both his Master and his Chapter, and allowing the Alpha Legion’s victory to become complete. Kersh failed to stop the Alpha Legion’s nearly-successful assassination attempt and crippling of Ichabod, and their theft of the Stigmartyr, the ancient and revered Chapter standard of the Excoriators dating back to the days of the Second Founding. This was a devastating blow to the Excoriators' morale, and the cause of many problems for the Chapter. Ichabod was severely injured during the failed assassination attempt. Though strong, the Chapter Master’s wounds were grievous, leaving him writhing in envenomed agony. The Alpha Legion’s assassination had ultimately failed, but they had employed a virulent toxin for which the Excoriators' Chapter Apothecarion had no record, nor antidote. Chapter Master Ichabod eventually succumbed to his ultimate fate.
- Kaurava Campaign (Unknown Date.M41) - The campaign for the Kaurava System saw the Blood Ravens pitted against the Imperial Guard stationed in the system and a Holy Crusade of the Order of the Sacred Rose of the Adepta Sororitas. Despite the presence of more than enough enemies in the form of the Orks of WAAAGH! Gorgutz, Eldar of the Craftworld Ulthwe, the Dark Eldar of the Kabal of the Black Heart, Chaos Space Marines of the Alpha Legion under the command of the Khornate Chaos Champion Firaeveus Carron, and the Tau, the Imperial forces present in the system wound up engaged in brutal infighting. To make matters worse, the Necrons had been slumbering under the sands of Kaurava III, a Necron Tomb World, for millions of years and were now led by the newly awakened Necron Lord of Kaurava. The campaign proved to be a disaster for the Blood Ravens, though how events unfolded remains uncertain in Imperial records. The Blood Ravens established their presence in the Kaurava System on the second world, Kaurava II. Recognising the strength and potential of the local inhabitants of the inhospitable mountains in which the Blood Ravens established themselves, the Chapter decided to examine the possibility of recruiting from these fairly barbaric inhabitants of the system's backwater. Unfortunately for the Blood Ravens, Captain Indrick Boreale was lost along with all 5 of the Blood Raven companies under his command, essentially costing the Chapter half of its manpower in a single campaign. As a result, the Blood Ravens desperately needed to step up their recruiting process in Sub-sector Aurelia, their only remaining recruiting ground for Neophytes who desperately needed to make good the Chapter's losses during the disastrous Kaurava Campaign. The survivors of the Kaurava Campaign in the Chapter would speak of it rarely, if at all, and viewed the campaign as a terrible mistake that deeply depleted the Chapter's strength.
All Space Marine Legions set arduous tasks and trials for potential recruits, but prior to the Horus Heresy the Alpha Legion set these initiation tests for squads, not individuals. Squads succeeded as a group or not at all - foolhardy heroics were frowned upon. The overall plan was paramount and more valuable than any one Space Marine.
The first batch of Alpha Legionaries was notably tall and strong even for members of the Astartes, physical attributes which suited Alpharius' focus on misdirection. For the Primarch put into place a directive that, as far as possible, all Alpha Legion Space Marines had to attempt to look alike; and the visage they patterned themselves on was that of Alpharius and Omegon. As a result, all Alpha Legionaries were at the very least shaven-headed, with many going so far as to have cosmetic surgical alteration. Their height also made it easier for them to be confused with the Primarch, although the twins were still the tallest in the Legion. When asked by non-Legion members, all Legionaries gave their names as "Alpharius", even when more than one was present.
This was an extension of the Legion's philosophy that they were a body of one that could strike in many places at once. This complete solidarity with each other expressed itself in other ways. Decisions within the Legion were made in a fairly open and reasonably democratic way, with all ranks - including the Alpha Legions' non-Astartes operatives - allowed to interject and comment freely during planning sessions. This freedom was allowed not just on military matters - the Alpha Legion internally discussed matters of philosophy and galactic policy that would have been forbidden or frowned upon in other Imperial institutions. Later recruits for the Legion were selected by the Primarch primarily based on high intelligence and personal initiative.
Effrit Stealth Squad
The Effrit Stealth Squad was a specialised infiltration unit within the ranks of the Alpha Legion that operated during the Great Crusade and Horus Heresy eras during the late 30th and early 31st Millennia. This elite force was formed from those Legionaries that specialised in infiltration, stealth, sabotage and assassination. These operatives were chosen for their adaptive thinking as well as their ability to improvise. The Effrit Stealth Squad was akin to the Legion Seeker Squads found within some of the Space Marine Legions, whose principal task on the battlefield was to identify an enemy's command structure, and slay these officers with a well-placed bolt round while the chaos of battle raged around them. The Alpha Legion are said to have been the first of the Legions to have developed this tactic and squad configuration, although its use sat poorly within the more honourable combat doctrine of some of the Legions like the Space Wolves. The Effrit Stealth Squad was personally led by Omegon, one of the twin-Primarchs of the Alpha Legion. Little else is known of this elite formation, as the Alpha Legion were notorious for the obfuscation and secrecy that surrounded the internal workings of their mysterious Legion.
The Alpha Legion was well known for their use of subterfuge and the innate ability of its Astartes and other operatives to blend-in with any environment. The Legion's agents mimicked those that they infiltrated to gather intelligence, perform sabotage, or plant disinformation. They also used more drastic measures, such as those employed during the Drop Site Massacre on Istvaan V during the opening days of the Horus Heresy.
Reveling in their anonymity, the Astartes of the Alpha Legion always strove to look alike, modeling themselves on their Primarchs Alpharius and Omegon who sought to keep their separate identities secret. The Alpha Legion's Primarchs had also devised an audacious plan to infiltrate another Space Marine Legion by using specially selected infiltrators. Prospective candidates for infiltration were selected for their possession of a variety of skills required for the successful completion of a mission, such as linguistic ability, a quick mind or an instinct for adaptation. These candidates would then take even more drastic steps to insure their ability to infiltrate their targets, having their minds reprogrammed psychically by the Legion’s Librarians so that they would forget their own true identities. The precautions taken by the psykers of the Alpha Legion shielded the infiltrator's mind from casual inspection by psychic or technological means.
During the Battle of Istvaan V, the Alpha Legion appropriated the bodies of many slain Raven Guard Astartes. Alpha Legion Apothecaries removed the faces from the slain Astartes and had them surgically grafted in place of an Alpha Legion infiltrator’s face; remolding the bone, tendons and muscles in order for the misappropriated face to be successfully implanted. To complete the façade, the infiltrator then ingested the flesh of the fallen Astartes, allowing their Omophagea organ to dissect and absorb the memories of the fallen Astartes. Bolstered by the abilities of the Librarians -- abilities forbidden by the Imperial anti-psyker edicts of the Council of Nikaea, but still widely practised by the Alpha Legion -- the infiltrators were able to gather what fragments they could of the dead Astartes’ life.
An infiltrator often did not know how many others were involved in a particular mission or whether or not they were successful in taking their assigned places; there could be a single operator or possibly dozens of operatives. It did not matter, for a lone Alpha Legion infiltrator was trained to act alone and act accordingly -- remaining alive and undetected until such time as it was prudent to communicate with someone from their Legion. Infiltrators were always prepared to give their lives for their Primarch and their Legion in order to successfully achieve the mission objectives assigned to them.
Once an Alpha Legion agent successfully infiltrated his assigned target, the operative had to take special care to stay constantly alert to maintain the façade that they had adopted. With the assistance of the Legion’s Apothecaries and the genetic material absorbed by their Omophagea, the operative’s vocal chords and mouth would be reshaped to better resemble that of the target whose identity he had assumed, as the genetically-enhanced hearing of a Space Marine could detect any small difference that might give rise to suspicion. Living amongst those they were assigned to infiltrate, each day an operative learned a little more about their foe -- small mannerisms, turns of phrase, and protocols -- that enabled him to blend in better with his fellows, but it was not an entirely perfect process.
As an infiltrator the operative understood what it meant to be a member of the Alpha Legion, and so did not expect to be lauded or singled out for his actions -- such glory-mongering was not in the Legion’s traditions. Each operative would fulfill their purpose, take contentment from the knowledge of a mission accomplished and the praise of their twin Primarchs, and become one of the anonymous many of the Legion once again.
The Legion also made a habit of recruiting non-Astartes specialists in every theatre and campaign they entered, commonly members of the other Imperial armed forces, though almost any human could be approached by the Legion for his knowledge or skills. These operatives often remained in their original position, ready to respond to Alpha Legion commands. Compromised operatives were not discarded if it could be avoided, and Alpha Legionaries would go to great lengths to retain them or hide their existence, lengths that included the fatal silencing of other Imperials. Alpha Legion operatives were tattooed with a small hydra symbol similar to the Legion badge.
Whilst known to have possessed Terminator and "stealth" squads (who appear to have worn blackened or dulled armour), the majority of the Legion appears to have armed and equipped themselves in a similar fashion unless tactically imprudent. The Alpha Legion were known to operate behind enemy lines and even mingle with enemy civilian populations. In such situations they were apparently able to pass unnoticed with a combination of appropriate dress and psyker mind-clouding.
Even less is known about the internal organisation of the Alpha Legion since the Horus Heresy than was known before. On occasions there have been successful assassinations of members of the Legion thought to be high-ranking officers, but their removal has had little visible effect on Alpha Legion operations.
The Legion's badge, the hydra, is a multi-headed mythical beast which could keep fighting even if one of its heads was cut off. This legend seems to reflect the Alpha Legion's command structure, as well as echoing its doctrine of multiple simultaneous attacks.Alpharius Omegon believed in planning and co-ordination, and the twins always sought alternatives and multiple solutions to any given problem, with different elements working together for the end result. These doctrines, thoroughly embraced by the Legion as a whole, have apparently been continued by the Traitor Legion warbands and have proved effective, especially in the disparate and secretive way they now operate. Extensive preparations are made before actually attacking an Imperial target, including using spies and corruption to weaken an enemy's resolve. Not only is an enemy attacked from every angle, but every attack is often coordinated to achieve the most destructive results. Many actions are planned to utilise and support local Chaos Cultist activity. These cults go to considerable effort to spread propaganda, perform sabotage, and carry out acts of unrest and rebellion, providing a distraction and weakening the enemy before the Alpha Legion strikes. Furthermore, the Legion has been known to ally themselves with anti-Imperial forces including other Traitor Legions and even xenos like the Dark Eldar. On worlds far away from the Eye of Terror, daemons are less relied upon since they cannot remain stable for long enough in the physical universe to be useful. If the Alpha Legion succeeds in securing the belief of a local Chaos Cult the cultists are summoned to add to the variety of their attacks.
Legion Combat Doctrine
The Alpha Legion's Primarch Alpharius' axiom was to attack one's enemy in as many diverse ways as possible, at the same time. In practice, this doctrine manifests in a variety of ways depending on the size of the operation and locale of the battle zone. Obfuscation and skullduggery are the Legion's mantra. The Alpha Legion has been known to employ devious tactics such as flanking maneuvers, tunneling to bypass enemy defenses, diversionary tactics, disguising troops and vehicles in enemy colours, air drops and teleportation behind enemy lines, infiltration, disabling enemy transport vehicles and routes, sabotage of essential supplies, ammo, food, and fuel depots, as well as atmospheric and ecological tampering, triggering seismic and tectonic activity, coercion, bribery of enemy troops and officers and Imperial officials, disguising and impersonating Imperial officers, enlisting enemy forces, distributing propaganda to incite civil unrest and outright rebellion, organizing anti-Imperial activity and supplying heretical groups and cultists, and allying themselves with corsairs, aliens and other Traitor Legions. Many of these unscrupulous tactics are employed by the Legion after careful coordination, often resulting in an elaborate and enigmatic strategy that leaves their enemies confounded and confused. Through the use of these completely unorthodox tactics the Alpha Legion is able to deploy smaller and more highly mobile forces than is normally necessitated, for the Legion employs actual combat as only one part of their overall strategy.
- "I am Alpharius."
- —Common greeting of all Alpha Legion Astartes when confronting outsiders
The Alpha Legion live by the tenets of their Primarch who believed that only through thorough planning and decisive coordination could one's ultimate objective be achieved. By having different elements working together in a cohesive and decisive force, the Legion is able to find alternative and multiple solutions to any given problem that may present itself. This nefarious doctrine has been wholeheartedly embraced by the entirety of the Legion, having proved to be brutally effective for millennia. During the early days when the Space Marine Legions came into existence, they had set grueling tasks and trials for potential recruits. Prior to the outbreak of the Horus Heresy, the Alpha Legion was known to set these initiation trials for entire squads, not individual candidates. They had to succeed as a group or not at all. If one failed, they all failed. Foolhardy or individual heroics were frowned upon, for the overall strategic plan is paramount and more valuable than any one Space Marine. It is not known if this practice is still carried out by the Legion.
Unlike the other Traitor Legions that reside in the Eye of Terror, the Alpha Legion's gene-seed is not plagued by the warping influence of Chaos, though there is still evidence of mutation in their gene-seed. It is unknown if there was such a problem with their gene-seed prior to the Horus Heresy; if so, it was kept concealed. It would not be surprising if the Legion did such a thing, due to their predilection for secrecy. During one well-documented battle during the Gothic War known as the Lethe Ambush, Alpha Legionnaires that were mutated were observed hiding their warped body parts, not out of any sense of shame, but as a form of subterfuge. The would only reveal their mutations once they were upon their enemies, adding shock and revulsion to their horrified enemies.
Notable Alpha Legionaries
- Alpharius (Deceased - Unverified) - Primarch of the Alpha Legion. The Power Armour worn by Alpharius was purposefully similar to that of any other Alpha Legionnaire.
- Omegon - Primarch of the Alpha Legion and also commander of the Effrit Stealth Squad. Large portions of Omegon's Power Armour and wargear were painted black and darkened. Omegon often operated under various disguises to keep secret the existence of the Alpha Legion's twin Primarchs.
- Arkos the Faithless, the Scion of Alpharius - Arkos the Faithless was a Captain of the Alpha Legion who turned Traitor along with the rest of his Legion during the Horus Heresy. Arkos is a Chaos Lord of the Alpha Legion and leader of the Alpha Legion warband known as The Faithless that intervened to support the Forces of Chaos during the Siege of Vraks. Following the defeat of the Chaotic forces on Vraks, the Faithless were destroyed and Arkos was taken prisoner by the Dark Angels Chapter of Loyalist Space Marines.
- Bale - Bale was the Chaos Lord who led an Alpha Legion warband to the Imperial Civilised World of Tartarus to find the ancient Chaotic artefact known as the Maledictum that met resistance from Captain Gabriel Angelos and the Blood Ravens Chapter of Space Marines' 3rd Company. Bale was slain by his own lieutenant, the Chaos Sorcerer Sindri Myr, who harboured his own ambition to use the Maledictum to become a Daemon Prince. (Deceased)
- Firaeveus Carron - Chaos Lord A Champion of Khorne that led his Alpha Legionnaire forces to launch a conquest of the Kaurava system. (Deceased)
- Mathias Herzog - Captain of the 2nd Company
- Dynat Crowbane - Following the tragic events of the Horus Heresy, during the unending bloodshed of the Great Scouring, the Traitor Chaos Warlord Dynat Mal, known as "Crowbane" for his ambush and slaughter of Raven Guard forces during the Battle of Lyx, flees to the Mandragoran Stars and gathers to him a coterie of Renegades, diabolists and Traitors thousands strong. Imperial forces sent in pursuit are repeatedly out-manoeuvred and cut apart piecemeal as Dynat's forces, now known as "The Shadowed Ones", employ guerrilla tactics and dark forces to extend their mastery over the region. After the vital Imperial outpost station at the world of Amarah in what is now the Orpheus Sector of the Segmentum Tempestus is attacked and destroyed, its entire population slaughtered and stockpiles plundered, any Imperial claim to the region is effectively severed. This sundered realm, caught beyond the light of the Imperium at the edges of the Veiled Region, becomes known as the Dark Marches and is benighted by ignorance and discord, and is shrouded from human sight.
- Sindri Myr - Sindri Myr was a Chaos Sorcerer who accompanied an Alpha Legion warband to the Imperial Civilised World of Tartarus to find the ancient Chaotic artefact known as the Maledictum that met resistance from Captain Gabriel Angelos and the Blood Ravens Chapter of Space Marines' 3rd Company. Sindri slew his own commander, the Chaos Lord Bale, and eventually used the power of the Maledictum to ascend to to become a Daemon Prince. However, he enjoyed this loft status for only a few moments before he was slain by the Blood Ravens' hero, Captain Gabriel Angelos. (Deceased)
- Nullus - Chaos Champion and lieutenant to the Daemon Prince Kernax Voldorius who was slain by the White Scars during the Hunt for Voldorius (Deceased)
- Ingo Pech - First Captain of the elite 1st Company
- Sheed Ranko - Captain of the Lernaean Terminator Squad
- Kernax Voldorius - Kernax Voldorius was an infamous Daemon Prince of the Alpha Legion who was hunted for decades by the White Scars Space Marine Chapter and its Captain of the 3rd Brotherhood, Kor'sarro Khan. After more than a decade on the hunt, in 865.M41 Kor'sarro Khan drove Voldorius from his foremost stronghold on the Hive World of Modanna to the world of Quintus, where Kor'sarro and the 3rd Brotherhood of the White Scars formed an alliance with Captain Kayvaan Shrike of the Raven Guard Chapter's 3rd Company, who also sought to dislodge the Alpha Legion's grip on that benighted planet. Together, the two Astartes officers and their companies ultimately ran the Daemon Prince to ground and slew him once and for all. Kor'sarro Khan took Voldorius' head back to the White Scars homeworld of Chogoris (officially known to the Administratum as Mundus Planus) where it was set on a pike on the road to the White Scars' fortress-monastery, so that all who saw it might know that no foe of the Chapter ever truly escapes the Emperor's justice. (Deceased)
The Alpha Legion are known to have possessed the following vessels:
- Alpha (Battle Barge) - Personal flagship of Lord Alpharius during the Great Crusade and Horus Heresy eras.
- Anarchy's Heart (Despoiler-class Battleship) - The Anarchy's Heart was the personal Battleship of the Chaos Lord Arkos the Faithless and his Renegade Chaos Space Marine warband, The Faithless. Arkos utilised the Anarchy's Heart to launch raids from the Eye of Terror across the millennia following the end of the Horus Heresy. This vessel was destroyed near the conclusion of the infamous Siege of Vraks by the Angels of Absolution Chapter's Battle Barge Liberatorii Delictum and the Strike Cruiser Repentant.
- Beta (Battle Barge)
- Lambda (Strike Cruiser)
- Occam's Razor (Strike Cruiser)
- Phi (Strike Cruiser)
- Upsilon (Strike Cruiser)
- Zeta (Strike Cruiser)
The Alpha Legion, unlike many of the Traitor Legions, maintained the same basic colour scheme for their Power Armour--blue, silver and green--even after their fall to Chaos. Alpha Legion Sergeants often had green helmets with a blue stripe down the center.
The Alpha Legion's Chapter badge before the Horus Heresy was one of the ancient Greek symbols for the letter Alpha. Following the start of the Horus Heresy, the Traitor Legion's badge became the hydra, the mythological multiheaded serpent that would grow back two heads for every one that was cut off.
The name Alpharius Omegon is drawn from "Alpha" and "Omega," the first and last letters of the Ancient Greek alphabet, which also represents the "Beginning" and the "End" in Greek mythology and Christian iconography. The Alpha Legion was also the "Legion Omega," the last of the 20 Space Marine Legions to be raised during the First Founding.
- Black Crusade: Tome of Fate (RPG), pp. 29, 32-33
- Codex: Space Marines (5th Edition), pp. 42-43
- Codex: Chaos Space Marines (6th Edition), pg. 12
- Codex: Chaos Space Marines (4th Edition), pp. 20-21
- Codex: Chaos Space Marines (3rd Edition, Revised Codex), p. 40
- Codex: Chaos Space Marines (3rd Edition, 1st Codex), p. 32
- Codex: Chaos (2nd Edition), pp. 14-15
- Deathwatch: First Founding (RPG), p. 78
- Imperial Armour Volume Five - The Siege of Vraks - Part One, pp. 16, 140
- Imperial Armour Volume Twelves - The Fall of Orpheus, pg. 16
- Inquisitor: Core Rulebook (RPG)
- Index Astartes IV, "The Enemy Within - The Alpha Legion Space Marine Legion"
- Realm of Chaos: Slaves to Darkness
- White Dwarf 310 (US), "Battle Report: The Defence of Cephian IV", pp. 94-113
- White Dwarf 277 (US), "Index Astartes: Alpha Legion"
- Legion (Novel) by Dan Abnett
- Deliverance Lost (Novel) by Gav Thorpe
- Age of Darkness (Anthology), "The Face of Treachery" by Gav Thorpe
- The Primarchs (Anthology), "The Serpent Beneath" by Rob Sanders
- Fear to Tread (Novel) by James Swallow
- Legion of the Damned (Novel) by Rob Sanders
- Warhammer 40,000: Dawn of War (PC Game)
- Warhammer 40,000: Dawn of War - Soulstorm (PC Game)