The Serpent's Coils
The Alpha Legion was the last of the Space Marine Legions to be raised and the last to be reunited with its primarch, and from the first it cultivated an aura of mystery it has never surrendered. It was led not by one gene-sire but by two, the identical twins Alpharius and Omegon, who concealed their duality so completely that the wider Imperium believed there to be but a single primarch. The twins encouraged every legionary to take up the name and the face of Alpharius, so that the loss of any one warrior meant nothing and the true commander could never be pinned down. To this day a captured legionnaire will meet his interrogator's gaze and name himself the primarch, and the maddening truth is that he might not be lying.
The Cabal's Bargain
The manner of the Legion's turning remains among the most disputed secrets of the Horus Heresy. It is widely held that Alpharius was approached by the Cabal, a xenos conspiracy that read the future in the shifting patterns of the stars and preached that the surest way to strangle Chaos forever was to let Horus win his war and then let mankind burn in its aftermath. Whether the Legion truly serves the Ruinous Powers, or merely wears their colours while pursuing some colder purpose of its own, is a question its own warriors may no longer be able to answer.
Warfare Without a Face
The Alpha Legion disdains the blunt instrument of a frontal assault. Its campaigns unfold as intricate webs of misdirection, in which cults are seeded across a world years in advance, loyal officers are blackmailed or quietly replaced, and populations are turned against their own defenders. When the Legion's Astartes at last reveal themselves, the battle is often already decided. They bear the coiled hydra as their emblem and the words Hydra Dominatus as their creed, a promise that for every head their enemies contrive to sever, two more wait unseen in the dark.
Chaos Space Marines
Order of battle
The Alpha Legion field the units of the Chaos Space Marines — a detachment from the roster:
Kindred formations
Other Chaos Space Marines formations
Black LegionThe Black Legion is the largest and most feared of all the Traitor Legions, forged from the ashes of Horus's own Sons of Horus after their primarch's death. Under the iron will of Abaddon the Despoiler, they cast aside their old colours and old shame, taking black armour to mark a new beginning. Where other legions cling to isolation and old grudges, the Black Legion draws in renegades of every stripe, uniting the fractured hosts of Chaos into a single crusading war-engine bent on the Imperium's utter destruction.
Crimson SlaughterThe Crimson Slaughter were once the Crimson Sabres, a rigidly disciplined Space Marine Chapter whose savagery on the world of Umidia drew the curse of Khorne upon them. Ever since, they have been haunted by the spectral voices of those they slew, a chorus of the murdered that no prayer can silence. Only in ceaseless bloodletting do the ghosts recede, and so the warband slaughters without end, dragging its damnation across the stars in a futile search for a moment's peace.
Iron WarriorsThe Iron Warriors are the master siege-breakers of Chaos, grim and pitiless engineers of destruction who reduce fortress worlds to rubble through overwhelming firepower and cold calculation. Once the Imperium's foremost specialists in siegecraft, they nursed a bitter resentment at being spent as siege-fodder while glory fell to others. That resentment curdled into treachery. Today they wage war as a science, favouring artillery, armour and attrition, and they take a grim satisfaction in proving that no wall, no matter how mighty, can stand against them forever.
Night LordsThe Night Lords are the terror-mongers of the Traitor Legions, waging psychological warfare with the same ruthlessness other legions bring to open battle. They strike from darkness in screaming lightning-marked craft, mutilating captives, broadcasting the screams of the dying, and leaving atrocities designed to shatter the courage of the living. To the Night Lords, fear is a weapon sharper than any blade, and a world paralysed by dread is a world already conquered. They fight not for the Dark Gods but for spite, survival and the sheer pleasure of the hunt.
Red CorsairsThe Red Corsairs are the largest renegade warband in the galaxy, a pirate empire that rules the warp-torn depths of the Maelstrom under the iron hand of Huron Blackheart. They are no ancient Traitor Legion but a wound torn open within living memory, born from the ruin of the Astral Claws Chapter after the fratricidal Badab War. Where insular Legions dwindle with the centuries, the Corsairs only grow, swelling their host with every raid, every renegade, and every captive broken and remade in Chaos.
The PurgeThe Purge are nihilist worshippers of Nurgle who cleave to only the darkest facet of the Plague God, despising life in all its forms and seeking not rebirth but annihilation. First appearing in the closing centuries of the 36th Millennium, they became convinced that the galaxy is beyond all saving and that purity can be found only in the sterile silence of death. Wielding poisons and engineered contagions, they wage genocidal war on human and xenos alike, praying for a plague that will scour every living thing from creation.
Word BearersThe Word Bearers are the zealots and prophets of Chaos, the first Legion to bend the knee to the Ruinous Powers and the architects of the entire Horus Heresy. Where other traitors war for vengeance or plunder, the Word Bearers war for faith, spreading the gospel of the Dark Gods across the galaxy with fire, scripture and sacrifice. Their Dark Apostles preach damnation to the masses and summon daemons to fight at their side, and they regard the destruction of the Emperor's atheist Imperium not merely as war but as a holy crusade of conversion.