List of Chaos Space Marine Warbands

The following is a list of all known Traitor Legions and Renegade Space Marine Chapters or warbands of Chaos Space Marines operating in Imperial space. The Traitor Legions are comprised of the original 9 Traitor Legions that betrayed their oaths of loyalty to the Emperor of Mankind during the ancient civil war called the Horus Heresy more than 10,000 standard years ago. The Traitor Legions were led by the Warmaster Horus Lupercal, once a Primarch of the Imperium and the Emperor's most trusted friend, son, and adviser before he was corrupted by the promises and lies of the Dark Gods and his own inner flaws.

The Traitor Legions are the most powerful component of the Forces of Chaos. The flesh and Power Armour of these Chaos Space Marines warped and twisted into new, darker and inhuman forms under the influence of the Chaos energies they were exposed to, as well as their shapes, which morphed to embody the corrupted Astartes' new allegiance. Following their defeat during the final epic battle, known as the Battle of Terra, the Emperor pronounced judgement upon the Traitor Legions. They were declared Excommunicate Traitoris.

Most of the remnants of the 9 Traitor Legions fled, along with the other Traitor Imperial forces that now served Chaos, chased by the Loyalist forces into an area of the galaxy where the Warp bled into realspace, creating the permanent Warp Storm known as the Eye of Terror. Due to the nature of Chaos, and the temporal instability of the Warp, many of the very same Chaos Space Marines who revolted against the Emperor more than 10 millennia ago continue to fight their Long War against the Imperium today, having effectively been granted a tortured immortality by the will of the Ruinous Powers.

Please note: Fan-created Chapters must be posted at the Warhammer 40,000 Fanon Wiki and not on this page. A separate list also exists for Loyalist Space Marine Chapters.

History
Renegade Chapters are made up of Chaos Space Marines whose Chapters or companies turned to Chaos after the end of the Horus Heresy, sometimes many millennia later. Some are not whole Chapters but simply warbands composed of a few tens or hundreds of Astartes drawn from the same original source and led by a charismatic commander or Chaos Lord. However, several of the Renegades listed here are simply Space Marine Chapters that have turned on the Imperium of Man or been unfairly declared Excommunicate Traitoris for one reason or another, but still view themselves as loyal to the Emperor of Mankind and not to the corrupt edifice of the Imperium His servants have built over the last 10,000 years. These types of Renegade Chapters are certainly no friends of Chaos or the other enemies of Mankind, though their lack of allies can often lead even the best-intentioned Renegades down the ultimate path of corruption to the willing worship of the Dark Powers, if only to secure their own survival when they are beset on all sides by enemies.

Through the passing of the centuries since the Horus Heresy, the Forces of Chaos have been further swelled by those Space Marines who have turned from service to the Emperor of Mankind to pursue their own agendas. Freed from the Imperial dogma and traditions of their Chapter, these so-called Renegade Space Marines fully indulge the needs of their superhuman bodies and their militant minds. They most often become corsairs, pirates and mercenaries, using their unparalleled combat skills to garner wealth and power for themselves, rising as tyrannical masters of pirate fleets and the masters of desolate frontier worlds. As they explore their new freedom from the discipline and strict purpose of the Adeptus Astartes, these Space Marines inevitably turn at some point to the Chaos Gods to gain more power to do as they will. From this point on, they are fated to walk the path of the Chaos Champion as much as any of the original Traitors of the Horus Heresy. These Renegades are hunted men -- loathed by all the other Space Marine Chapters, who consider it their foremost duty before the Emperor to destroy any Renegade Astartes lest their vile shame and dishonour leave a black stain upon all the Loyalist Space Marines who have never turned their face from the light of the Emperor or their duty to Mankind for their own selfish gain.

Though never equal in size or power to the original Legiones Astartes, a modern Space Marine Chapter is a potent military force in its own right and when an entire Chapter turns Renegade it presents a grave threat to the Imperium. With all the resources of a Space Marine Chapter at their disposal, the Renegades of Chaos destroy Imperial armies, conquer Imperial worlds and despoil whole Sectors of the Imperium. Such events warrant an extreme response from the Imperial forces, not to mention the other, Loyalist Space Marine Chapters. It is perhaps the greatest test of faith for a Space Marine to fight another Astartes and these internecine conflicts often have a terrible effect on other nearby Chapters. In these circumstances, such inter-Chapter wars tend to escalate quickly, engulfing many worlds with bloodshed. On occasion, those forces sent to deal with the Renegade Chapter may actually end up, in whole or in part, becoming corrupted and joining with those they were sent to destroy, just as happened to many among the Traitor Legions so long ago.

An example of just such an outcome infamously took place in the 34th Millennium during the Obscuran Uprisings. During the curse of 400 Terran years of anarchic separatist rebellions that shook much of the Segmentum Obscurus, at least 7 Loyalist Space Marine Chapters broke their oaths to the Emperor and took part in the looting and pillaging of hundreds of these Imperial worlds. Of these Chapters, 2 of them, the Sons of Vengeance and the Silver Guards -- had at first fought on the side of the Imperium but turned Renegade after their vicious retaliatory actions against the rebel Free Council of Hannedra II. It is believed these Chapters found great freedom in unleashing their full wrath at Hannedra II and they soon gave up any pretense of serving the Emperor in subsequent brutal actions unleashed across the Segmentum.

Chaos Space Marine Traitor Legions
Each of the 9 Astartes Traitor Legions fights using a different style of warfare that is defined by their Legion's culture and nature; also, 4 of the 9 -- the Emperor's Children, the World Eaters, the Thousand Sons and the Death Guard -- are dedicated specifically to the service of 1 of the 4 major Chaos Gods, Slaanesh, Khorne, Tzeentch and Nurgle, respectively. The other 5 Traitor Legions essentially serve the interests of all of the Ruinous Powers collectively in the form of Chaos Undivided.

The 9 Chaos Space Marine Traitor Legions who joined the rebellion of the Warmaster Horus against the Emperor -- fully one half of the Space Marine Legions created during the First Founding -- are (in order of their Founding):

The Emperor's Children
The Emperor's Children were one of the earliest of the Space Marine Legions to declare itself for Horus and his Traitors, fighting at his side against its own Loyalists during the Istvaan III Atrocity and against the Loyalist Legions during the Drop Site Massacre on Istvaan V. The III Legion and its Primarch Fulgrim had been corrupted following its encounter with the Slaanesh-worshipping xenos race known as the Laer and their world of Laeran late in the Great Crusade. The rot spread quickly through the Legion, and the Emperor's Children embraced Chaos, particularly the Prince of Pleasure, in all its depravity. Little trace can now be seen of the original armour and equipment of the Emperor's Children, covered as it is by skins of iridescent fur or scales, jewels, or the fantastical renderings of screaming faces or rutting beasts. The Emperor's Children fight for sensation and sensory overload, bringing a clashing cacophony of sound, colour, and energy to the battlefield.

The Iron Warriors
The Iron Warriors once formed the Emperor's legion of siege troops. They fought on a hundred worlds in the Great Crusade, laying siege to alien citadels and the palaces of Heretics with equal gusto. The Iron Warriors Primarch, Perturabo, excelled in the arts of siege and trench warfare above all else, and his treatise on fortifications and their reduction formed the basis of several sections of the Tactica Imperialis. The Iron Warriors betrayed the Emperor on Istvaan V, their mazes of bunkers and razor wire becoming a death trap for their Loyalist brethren instead of the sanctuary they promised to be. The Iron Warriors wear relatively unadorned armour that is commonly pieced together from the older marks for its heavier frontal protection. They favour heavy weaponry like Lascannons or Missile Launchers for long-range engagements, although well-equipped Iron Warriors Assault Squads are also rightly feared.

The Night Lords
Led by their saturnine Primarch, Konrad Curze (also known the Night Haunter) the Night Lords were greatly feared even before the Heresy. Curze believed in the use of terror as a weapon and his foes quickly learned to fear the night. The Night Lords were one of the first Legions to join Horus' rebellion, turning on what they saw as a weak-willed Emperor incapable of having the strength to lead. Even after Horus' defeat the Night Lords have continued to wage an unremitting campaign of terror against the Imperium. The Night Lords refuse to follow any of the Chaos Gods, and have become cynical, hard-bitten, and frighteningly ruthless warriors. They fight for the pleasure of it, and for the material rewards it can bring, and not for the worship of some deity. They look down upon their more dedicated brethren, whether they are fanatical Chaos Space Marines like the World Eaters, or zealous Loyalist Space Marines like the Dark Angels.

The World Eaters
Under the Primarch Angron, the World Eaters underwent psycho-surgery that transformed an already fierce legion into bloodthirsty berserkers through the use of cortical implants known as the Butcher's Nails pioneered on their Primarch's homeworld of Nuceria. When they betrayed the Imperium, it was of little surprise that the vast majority dedicated themselves to Khorne. The XII Legion fractured after the Heresy, scattering into warbands across the galaxy. However, any member of the World Eaters is likely to be bloodthirsty and violent. As is fitting to their patron God, the World Eaters wear armour as red as arterial blood, edged with brass and decorated with skulls and symbols of Khorne. Most disdain long-ranged warfare, preferring to close with the enemy to kill them with Chainaxe, Power Sword, and (if need be) Bolt Pistols.

The Death Guard
The Death Guard followed Horus into heresy, their sense of loyalty to their Warmaster and their Primarch, Mortarion, triumphing over their duty to the Emperor on distant Terra. The rebel Death Guard Legion was marooned in the Warp during the long journey to Terra to join the attack on the Imperial Palace. A mysterious, unstoppable contagion spread through the trapped fleet, putrefying all it touched. Mortarion himself became infected and in his delirium he called upon the Powers of Chaos to aid his Space Marines. Mortarion's fevered ravings were answered by Nurgle, and Mortarion became Nurgle's foremost mortal Chaos Champion and eventually his Daemon Prince. The Death Guard survived but they continue to bear the marks of Nurgle's first blessings upon them. Their once-white armour became stained and cracked where the bubbling foulness of their mortal bodies has erupted to the surface. They bear the three-lobed mark of Nurgle rendered as flies or rotting heads upon banners and shoulder guards. Their Bolters and Chainswords are caked with filth and rust but are no less deadly. Plague and contagion have become the Death Guard's primary weapons and they can be found anywhere in the galaxy spreading Nurgle's foul blessings.

The Thousand Sons
The path to damnation for the Thousand Sons Legion of Space Marines was longer than most, but its final plunge more complete than any. Even before the Horus Heresy the Sons' cyclopean Primarch Magnus the Red led his sons in the study of arcane lore and the practice of sorcery despite the Emperor's disapproval and the outright ban on such practices at the Council of Nikaea. When Horus gathered his forces, the Thousand Sons tried to use their occult powers to warn the Emperor of the Warmaster's betrayal. Disastrously the Emperor was mistrustful of anything tinged by Chaos such as the use of psychic sorcery that He had expressly forbidden at Nikaea and He declared the Thousand Sons Primarch to be taken captive and brought back to Terra for his disobedience. Leman Russ and the Space Wolves Legion were sent to devastate the Thousand Sons' homeworld of Prospero. To survive and protect their accumulated wisdom, the Thousand Sons sought the patronage of the Chaos Power Tzeentch, the Changer of the Ways, greatest master of magic among the Chaos Gods. During the terrible battle known as the Burning of Prospero, Tzeentch transported Magnus and his surviving sons to the Daemon World in the Eye of Terror called the Planet of the Sorcerers. The surviving Thousand Sons have been split by internal schisms, their pursuit of occult knowledge estranging them from each other and even their cyclopean Primarch. A cabal of renegade Sorcerers led by their former Chief Librarian Ahriman unleashed a great magic upon the Legion to prevent further mutation and corruption of its members by Chaos. This Rubric of Ahriman however reduced most of the Thousand Sons to soulless suits of animated armour known as Rubric Marines, but left the surviving Sorcerers unmatched in power.

The Black Legion
The Black Legion is the only Traitor Legion to have changed its name in its ten thousand years of exile. In the First Founding the XVI Legion was created as the Luna Wolves. The Emperor subsequently allowed His favoured son Horus to rename the Legion the "Sons of Horus" in recognition of its accomplishments in the Ullanor Crusade and in honour of its Primarch. The Sons of Horus willingly followed their beloved Primarch and Warmaster into rebellion, fighting at the very forefront of his most important campaigns. When Horus was defeated by the Emperor at the Battle of Terra, the Legion's morale was shattered; their patron, their father, was gone. After the battle for the Imperial Palace the Sons of Horus renamed themselves the Black Legion, changing their Legion colours to black in memory and mourning of their fallen Primarch. They gave themselves to the worship of one Chaos Power after another and lost many of their number through possession and madness. The hardened survivors lead warbands against the Imperium to this day, still eager to expunge the bitter memory of Horus' defeat. The Black Legion has been reforged under the strong leadership of Abaddon the Despoiler, the former First Captain of the Sons of Horus, who has claimed Horus' mantle as the Warmaster of Chaos Undivided.

The Word Bearers
Lorgar, Primarch of the Word Bearers Legion, was a scrupulous and dedicated follower of the Imperial Cult, and in many ways was the founder of the religion of Emperor-worship called the Lectitio Divinitatus that would one day become the Adeptus Ministorum. He led his XVII Legion in the building of vast monuments and immense rituals during the Great Crusade to secure the faith of those that were conquered in the God-Emperor. The Emperor rejected Lorgar's efforts however, telling him that He needed His Space Marines to fight and serve the secular Imperial Truth which disdained all religion and superstition, not worship Him. Lorgar's disillusionment with the Emperor's impiety drove him to worship of the Chaos Powers during the Pilgrimage of Lorgar undertaken some 43 standard years before the start of the Horus Heresy, entities that truly demanded worship and sacrifice from their followers. When Horus raised his banner the Word Bearers, who had largely driven Horus into corruption by Chaos from behind the scenes, eagerly followed him into rebellion along with a thousand hidden Chaos Cults they had established on the worlds they had brought into Imperial Compliance in the last days of the Great Crusade. The Word Bearers' fanatical zealotry has become dedicated to the worship of Chaos in its purest form, unadulterated by the veneration of any particular Chaos Power over the others. They are the only Traitor Legion that still maintains the rank of Chaplain, the darkly twisted individuals holding this office now known as Dark Apostles and leading their brethren in heretical prayers and insane catechisms. Immense cathedrals and rune-etched monuments still rise in the wake of the Word Bearers' conquests, but now they are blasphemous dedications to the glory that is Chaos.

The Alpha Legion
The Alpha Legion was the twentieth and final Legion created in the First Founding. During the Great Crusade the XX Legion earned renown for its strict discipline and organisation. The Alpha Legion strove hard to outshine its brethren in all things and prove its worthiness to be among the older Legions. The war-lust of the Alpha Legion easily led them into heresy when Horus declared himself against the Emperor, though some legends say that the Alpha Legion secretly remains loyal to the Emperor in perhaps the greatest of the many deceptions and ploys it has worked. Here at last was their chance to prove themselves against opponents just as tough, as battle hardened, and ferocious as themselves. The Alpha Legion did much to ravage the Eastern Fringe during the Heresy, pursuing its own set of objectives far from Terra. In the ten millennia since they have continued to strike from bases hidden all over the galaxy. Unusually the Alpha Legion actively cultivates Chaos Cultists and rebels, multiplying their impact many times over. The Inquisition holds a special loathing for the Alpha Legion for their part in spreading Chaos Cults and fanning the embers of heresy into the raging fires of outright rebellion.

Q
No known Renegade Chapters starting with "Q".

X, Y, Z
There are no known Renegade Chapters starting with "X", "Y" or "Z".