The galaxy's greatest betrayal
The Horus Heresy
The Age of Darkness — the civil war that shattered the Emperor's dream as the Warmaster Horus turned half the Legiones Astartes against Terra.
Factions
Warhammer 40,000 sub-setting
Alpha LegionLegiones AstartesMasters of deception and the hidden blade, the Alpha Legion wage the Horus Heresy through subterfuge and misdirection, their true allegiance known only to their twin primarchs.
Blood AngelsLegiones AstartesThe most beautiful and beloved of the Legions, the Blood Angels followed the winged Sanguinius from the irradiated wastes of Baal to the daemon-haunted trap of Signus, carrying a hidden thirst no perfection could wholly conceal.
Dark AngelsLegiones AstartesThe secretive First Legion, sons of Lion El'Jonson, wielded terror weapons and the six wings of the Hexagrammaton as they held to their loyalty through the Heresy's long shadow.
Death GuardLegiones AstartesGrim survivors turned instruments of plague, the Death Guard followed Mortarion from the Great Crusade's attritional wars into betrayal at Istvaan III and Nurgle's rotten, deathless embrace.
Emperor's ChildrenLegiones AstartesThe most admired of Legions, sons of Fulgrim, whose flawless pursuit of perfection curdled into the boundless excess of Slaanesh and open betrayal.
Imperial FistsLegiones AstartesUnyielding masters of siegecraft and fortification, the Imperial Fists held the Emperor's Palace itself against the Warmaster's onslaught, embodying a doctrine of stubborn, immovable defiance.
Iron HandsLegiones AstartesGrim masters of iron and augmetic who held flesh itself to be a weakness to be cut away, the Iron Hands were shattered into a leaderless brotherhood of vengeance when their primarch Ferrus Manus was beheaded at Isstvan V.
Iron WarriorsLegiones AstartesThe Imperium's unrivalled masters of the siege, sons of Perturabo, whose grim endurance and unhealed resentment carried them from thankless labour into open treachery.
Legio CustodesTalons of the EmperorThe Legio Custodes are the Emperor's own golden praetorians, ten thousand individually wrought demigod-warriors who guard Terra and the person of the Master of Mankind against every threat the cosmos can turn against Him.
Legio TitanicusCollegia TitanicaThe Titan Legions of the Collegia Titanica were the Imperium's god-engines, walking war-machines whose Princeps merged with their Titans and who split loyalist and traitor when the Heresy came.
MechanicumMechanicum TaghmataThe Mechanicum is the ancient priesthood of Mars before it became the Adeptus Mechanicus, a machine-worshipping empire of tech-priests and battle-automata whose forge-hosts armed the Great Crusade and tore themselves apart in the Heresy.
Night LordsLegiones AstartesBorn of a lightless world and a broken primarch, the Night Lords wage war as terror made method, breaking the will of the living long before they trouble to take their lives.
Questoris KnightsQuestoris FamiliaThe Knight Households of the Great Crusade were a martial aristocracy of towering war-suits, piloted by noble scions sworn to Terra or turned traitor when the Heresy shattered their ancient oaths.
Raven GuardLegiones AstartesSilent masters of the lightning raid and the liberation of the oppressed, the Raven Guard are all but annihilated at Isstvan V and left to rebuild from shadow.
SalamandersLegiones AstartesMaster artificers and champions of the innocent, the Salamanders of Nocturne wield fire and forge-craft in the Emperor's name until the Drop Site Massacre burns their Legion to embers.
Sisters of SilenceTalons of the EmperorThe Sisters of Silence are the Emperor's blank-souled Null-Maidens, a martial sisterhood of pariahs bound by a vow of silence whose very presence strangles sorcery and unmakes the witch.
Solar AuxiliaImperialis AuxiliaThe void-hardened elite of the Imperialis Auxilia, the Solar Auxilia were the finest mortal soldiery of the Great Crusade, the disciplined human spearhead that marched beside the Legions to conquer the stars.
Sons of HorusLegiones AstartesOnce the Emperor's finest sons, the Sons of Horus followed their primarch into damnation, becoming the first and most feared instrument of the Warmaster's galaxy-splitting rebellion.
Space WolvesLegiones AstartesThe Emperor's executioners, the Space Wolves are the leash and the blade of the Imperium, a savage brotherhood of storm and fang loosed upon whatever their master decrees must die.
Thousand SonsLegiones AstartesThe XV Legion turned the pursuit of forbidden knowledge into an art of war, and were damned for it, cast down at Prospero by the very Emperor they sought to warn.
UltramarinesLegiones AstartesThe XIII Legion forged the greatest civilisation of the Great Crusade in the five hundred worlds of Ultramar, only to be gutted at Calth by the treachery of a brother Legion.
White ScarsLegiones AstartesStorm-born horsemen of the stars, the White Scars ride the void as they once rode the plains of Chogoris, striking without warning and vanishing before the wound is felt.
Word BearersLegiones AstartesThe XVII Legion answered the Emperor's rebuke of their faith by finding gods who wanted worship, becoming the first and most deliberate architects of the Horus Heresy.
World EatersLegiones AstartesEnslaved gladiators reforged into living weapons, the World Eaters marched behind the rage-maddened primarch Angron and his Butcher's Nails down a red road that led, inexorably, to the blood-drenched altar of Khorne.