In Games Workshop's Warhammer Fantasy and Warhammer 40,000 fictional universes, Chaos refers to the parasitic entities which live in a different plane of reality, known as the Warp in Warhammer 40,000 and as the Realm of Chaos in Warhammer Age of Sigmar. The term can refer to these warp entities and their influence, the servants and worshippers of these entities, or even the parallel universe in which these entities are supposed to reside. The most powerful of these warp entities are those known as the Chaos Gods, also sometimes referred to as the Dark Gods, Ruinous Powers, or the Powers of Chaos. Similarities exist between the Warhammer idea of Chaos and the concept of Chaos from Michael Moorcock's Elric saga, which also influenced D&D's alignment system. Further similarities can be seen with the godlike extradimensional Great Old Ones of horror writer H. P. Lovecraft's stories.
- 1 Realm of Chaos
- 2 Conceptual origins
- 3 Chaos Gods
- 4 Chaos Space Marines
- 5 Warhammer 40,000
- 6 Warhammer Age of Sigmar
- 7 See also
- 8 Notes
- 9 References
- 10 Bibliography
Realm of Chaos
The first version of Realm of Chaos is a two-volume publication by Games Workshop concerning the forces of Chaos. The hardback books contain background material and rules for Warhammer Fantasy Roleplay (1st edition), Warhammer 40,000: Rogue Trader and Warhammer Fantasy Battle (3rd edition).
It consists of the 1988 book Slaves to Darkness and the 1990 follow-up The Lost and the Damned. Each of the two volumes describe the background and associated rules for a pair of antagonistic Chaos gods but each also had material that was germane to Chaos in general in the game settings. Both were written by Rick Priestley, Bryan Ansell, Mike Brunton and Simon Forrest although many more people contributed material, both writings and illustrations. The cover art of Slaves to Darkness was painted by John Sibbick and The Lost and the Damned by Les Edwards. The process in sketching and designing the cover for The Lost and the Damned was investigated within the volume. This was not the case for Slaves to Darkness.
The second version of Realm of Chaos was a boxed set released in 1995 covering all of the rules for the Chaos armies (Beastmen, Warriors, and Daemons) in Warhammer Fantasy. The box also contains the magic spell cards and items for the army.
Slaves to Darkness
It also features rules on the creation of Chaos Champions and their warbands, Daemon weapons, demonic possession and the Horus Heresy of WH40K. To give flavour for the background and attributes of followers of Chaos it contained material such as a list of over 120 "Chaos Attributes" - mutations that the followers of Chaos were often afflicted by. This included some mutations that were advantageous, such as those that made the mutant extra strong or taller, and those that confer a disadvantage, such as ones that made the mutant small, weak or stupid. Other mutations were purely cosmetic, such as giving the mutant brightly coloured skin or eyes on stalks, whilst some mutations were clearly comical, such as one that gave the mutant a silly walk (possibly inspired by the Monty Python sketch The Ministry of Silly Walks) and even a mutation that bestowed the "gift" of uncontrollable flatulence.
It introduced the Imperium's Daemonhunters of the Ordo Malleus and their associated Space Marine chapter - the Grey Knights.
The volume is also notable for having provided the first complete and coherent narrative of the Horus Heresy, an event which, albeit mentioned as the background justification of the internecine battles featured in the 1/300 scale boxed wargames Adeptus Titanicus and Space Marine, lacked a proper explanation in the WH40K milieu at large.
The Horus Heresy firmly locked the concept of chaos and demon influence in the SF universe of WH40K for good, establishing, as a consequence, that the "Realm of Chaos" was actually the Warpspace that intergalactic farers had to traverse in order to defeat the relativistic distances involved in space voyage.
The link between the Warhammer and Warhammer 40,000 worlds is explicitly stated in the first pages of the book.
The Lost and the Damned
The Lost and the Damned covers the background material and Daemons for the other two major Chaos gods Tzeentch and Nurgle. In addition, it contains rules that allow players and game masters to create their own gods and appropriate Daemons. The additional section introduced important elements for Warhammer 40,000, giving background on the early life of The Emperor as well as rules for the Sensei, immortal children the Emperor fathered during his thousands of years of life before he ascended the Golden Throne, who are champions of the cause of "good". The Sensei have since been written out of the Warhammer 40,000 background, although an explanation for their extermination was given as an Easter egg of sorts in the third edition of the Warhammer 40,000 rulebook.
Both volumes also have army lists for Chaos armies and painting guides for miniature figures. They also introduce the idea of daemonic battles, which consist of armies formed primarily from daemons and other immortal followers of Chaos and fought within the realms of Chaos itself.
Each was heavily illustrated and interspersed with many short stories related to Chaos. The Lost and the Damned featured the tale of the Horus Heresy's climax and an illustration of the Emperor's climactic battle with Horus. 
The two books contained a significant amount of violence and sex (although the latter was implied rather than explicit), particularly Slaves to Darkness, which featured Khorne, the god of violence and killing, and Slaanesh, god of pleasure and sensation. Though in the UK Slaves to Darkness carried the note "suggested for mature readers" on its cover, The Lost and the Damned did not. Labelling it as "mature content" was a guide for vendors as sales to minors was not legally restricted.
Slaves to Darkness features grotesque illustrations by artists such as Ian Miller, Adrian Smith, John Blanche, Tony Ackland and Tony Hough. As the subject matter of the book focused on the gods of violence and pleasure, the illustrations were likewise violent or perverse. The Lost and the Damned featured much more toned down artwork, although some was reused from Slaves to Darkness.
Games Workshop stopped publishing the books within a few years. It has been suggested that this was because, in the mid-1990s, Games Workshop began to try to appeal to younger gamers (hence diluting the mature content), rather than only to adults, and the explicit violence of the Realm of Chaos books was seemingly inappropriate for the younger market. Another suggestion is a more prosaic explanation: the Warhammer Fantasy game was revised and re-released in its fourth edition in 1992, an edition which rendered the rules in all the third edition supplements, including Realm of Chaos, obsolete. Warhammer 40,000 was revised along similar lines in 1993. The books are consequently quite rare, with The Lost and the Damned being much the rarer of the two. The reason for this is that a copy of Slaves to Darkness was required to use much of the material in The Lost and the Damned, whereas the former book could be used on its own, and was also released two years earlier than its companion volume. Hence Slaves to Darkness was reprinted twice after its initial release whereas The Lost and the Damned received only a single print run. For more extended and deeper reference lore material on the nature of the Hordes of Chaos, the Realm of Chaos books have been replaced by the newer volume The Liber Chaotica, published by Black Library Publishing.
Warhammer Fantasy, Warhammer Age Of Sigmar, and Warhammer 40,000 depict universes that are out of spiritual and emotional balance. The concept of Chaos Gods has been more or less integral to both ever since they were first conceived. The Chaos Gods in Warhammer are essentially deities worshipped and feared by various groups and that is what makes these groups followers of Chaos. In this idea there is evidently a strong influence from the English fantasy writer Michael Moorcock. Many different Chaos Gods were named in the various early miniature catalogues released by Citadel in the early eighties. But it was never clearly explained what the fictional pantheon looked like. The idea of "Four Great Powers of Chaos", i.e. Chaos Gods, was first introduced in the two Realm of Chaos sourcebooks released 1988 and 1990 respectively. To date these remain the original and amongst the most detailed pieces of work published by Games Workshop regarding Chaos. The Black Library "artbooks" of the Liber Chaotica series (released from 2001 to 2006) and Black Industries' Warhammer Fantasy Roleplay supplement, the Tome of Corruption: Secrets from the Realm of Chaos (published 2006) contain as much detail as the original Realms of Chaos sourcebooks (and, in the case of the Liber Chaotica, taken directly from the original books), but with the various additions and changes to the Chaos imagery that GW has introduced over the years – although these latter two books focus mainly upon Chaos as perceived through the Warhammer Fantasy imagery. A major factor in both universes about Chaos is that all four of the gods represent things that are good in moderation, but are taken to extremes. For example, Nurgle is the god of life, but the unrestrained, unwholesome life, such as a tumor.
The main four Chaos Gods appear in both Warhammer 40,000 and Warhammer Fantasy. The two settings are not actually related to each other despite their names, but in concept the Chaos Gods are similar in both.
- Khorne: the Chaos God of bloodlust, war, death, blood, honour in battle, and skulls. Khorne favours close combat, abhorring wizards (in Warhammer Fantasy) or psykers (in Warhammer 40,000), considering them to be gaining unfair advantages. His Dark Tongue name, "Kharneth,", means the Lord of Blood. Khorne is also the god of courage and honor, but these trappings are often eventually discarded in favor of the primary goal of killing. While he blesses his followers by granting them strength and martial prowess, Khorne does not truly care who spills blood, so long as the blood continues to be spilled. His material form is a mighty being wearing brass armor and sitting on a throne of skulls. His holy number is 8 and his main enemy god is Slaanesh. Those who worship Khorne are mighty warriors seeking to earn his favor by slaying mighty beasts and murdering mass populations. His main daemons are the Bloodletters (his soldiers), Flesh Hounds (his beasts), and Juggernauts (his daemonic, metallic steeds). They are led by massive Greater Daemons called Bloodthirsters. His realm is described to be a giant killing field with warriors constantly fighting and dying at his feet. His followers often use "blood for the blood god, skulls for the skull throne" as their battle cry.
- Tzeentch: the Chaos God of change, fate, mutation, hope, and knowledge. Tzeentch's followers are powerful sorcerers who prefer to channel the energies of the Warp (Warhammer 40,000), or Winds of Magic (Warhammer Fantasy) at a distance rather than get close to enemies. Tzeentch is always scheming, his every action feeding into his great plots that only he can comprehend. Tzeentch controls and manipulates the fates of all and weaves them intricately into his devious web of manipulation and hunger for power. He has no material form, as it constantly shifts and changes. His holy number is 9 and his main enemy god is Nurgle. Those who worship Tzeentch are sorcerers and magicians hungry for knowledge and the pursuit of a greater understanding of the universe. His main daemons are the Horrors (his soldiers), Flamers and Screamers (his beasts), and Discs (his flying, metal discs). They are led by avian Greater Daemons called Lords of Change. His realm is described as a maze that constantly shifts and distorts, leading people entering into unimaginable levels of madness.
- Nurgle: the Chaos God of plague, despair, disease and death. Nurgle is a warm and welcoming god who gifts his followers with poxes and boils, rashes and sores. His Dark Tongue name, "Nurghleth", means the Lord of Decay. His power comes from the inevitability of death and decay, and Nurgle is often referred to as 'Grandfather Nurgle', as entropy is the most ancient of forces, and he is the only one who cares for his followers. Nurgle thrives in death and decay, growing more powerful as great plagues spread, and his servants seek only to spread disease. Nurgle prides himself on the achievements of his followers, "gifting" them with hideous diseases while sheltering them from pain, and his followers rejoice in their blessings, shrugging off lethality and disfigurement in a state of rapturous undeath. People in sickness might pray to Nurgle for relief, but rather than heal the sick, Nurgle helps them endure their illness by removing their pain and misery, all the while exacerbating their physical degeneration. His physical form is a large blob of putrid sickness and disease. His holy number is 7 and his main enemy god is Tzeentch. Those who worship Nurgle are those suffering and wanting freedom from sickness and pain, unaware that they are rapidly becoming more sick yet feeling less pain. Nurgle welcomes all who desire to worship him. His main daemons are the Plaguebearers (his soldiers), his Nurglings (smaller, minuscule versions of himself), his Beasts, and his Rot Flies (his flying, disgusting beasts). They are led by Greater Daemons known as Great Unclean Ones, which are physically manifestations of himself in the material world. His realm is described to be a massive rotting garden filled with death and decay. It is said that he has captured the Eldar (Elven) goddess Isha, who whispers the cures of Nurgle's plagues to those in the material realm.
- Slaanesh: the Chaos God of lust, pleasure, desire, and excess. In both settings, he is the youngest of the four gods; he is typically considered androgynous, and while he is usually referred to as being male, in the Warhammer 40,000 universe, the Eldar races consider him to be female. His Dark Tongue name, "Slaaneth", means the Prince of Pleasure. His followers seek only to indulge in whatever fleeting whims and desires they feel, and they tend to become graceful, beautiful warriors who harbor selfish, cruel souls. In the Warhammer 40,000 background, he was birthed from the excesses and hedonism of the Eldar society. His birth created a psychic shockwave that spread across the galaxy, killing most of the Eldar population and their gods; the survivors split into the various Eldar factions. It also created the largest warp storm in the Milky Way, the Eye of Terror, which later became the main residence of the scattered Chaos Space Marines. The fall of the Eldar empire paved the way for the rise of the Imperium of Man. In Warhammer Fantasy, his followers are partly responsible for the corruption of an important Elven leader named Malekith, and the subsequent schism that led to the formation of the Dark and High Elf races. His physical form is an androgynous being of the most physical beauty. His holy number is 6 and his main enemy god is Khorne. Those who worship Slaanesh are those who either wish to achieve the most popularity amongst their fellow men or the most ecstatic pleasure, pleasure beyond imaginable. His main daemons are the Daemonettes (his soldiers), the Fiends (his beasts), and his Steeds (his serpentine mounts). They are led by Greater Daemons called the Keepers of Secrets, lithe creatures with unholy beauty. His realm is described to be a massive castle in the middle of seven circles, each representing one of the classical seven deadly sins. People cannot make it through without succumbing to some type of flaw.
In addition to these Chaos Gods, Warhammer: Age of Sigmar (the sequel game to Warhammer Fantasy) features a number of new members who have ascended to the Chaos Pantheon:
- Malice: the Chaos God of anarchy, also known as Malal in early Warhammer canon, is one of the most disputed and lesser known of the Chaos Gods. He represents the anarchical nature of chaos, and so seeks to displace his fellow gods completely. While he does not appear in Warhammer: Age of Sigmar or Warhammer Fantasy, there is a Chaos Space Marine warband in Warhammer 40,000 called the Sons of Malice, which are his followers. His holy number is 11.
- The Great Horned Rat: the Chaos God of blight and pestilence, is a recent addition to the Chaos Pantheon, only found in the universe of Warhammer: Age of Sigmar. After the destruction of the Old World and the capture of Slaanesh, the god of the chaos race known as the Skaven, the Horned Rat, was renamed the Great Horned Rat and made a Chaos God. He longs for the destruction of civilization and desires for the respect and becoming the equal of his brother gods, who look down upon him. His physical form is a gigantic anthropomorphic rat. His holy number is 13. The only ones who worship him are the race called the Skaven, half rat and half man monstrosities who formerly living under the earth of the Old World, now spread throughout the Mortal Realms. His main daemons are the Skaven themselves (his soldiers) and their monstrous beasts and machines that they have created. They are led by "enlightened" priests called Grey Seers and large Greater Daemons called Verminlords, gigantic rats armed with armor and large weaponry.
- Hashut: the Chaos God of darkness. Known as the Father of Darkness, Hashut is the god of the Chaos Dwarfs, now stylized as the Legion of Azgorh. He is described to have a brazen bull head and rules a great city called Zharr-Naggrund, the City of Fire and Desolation. His main followers are the chaos dwarfs and he has some daemons, notably bovine like monstrosities such as the Lammasu and the Great Taurus.
Chaos Space Marines
In the table-top wargame Warhammer 40,000, the Chaos Space Marines or Chaos Marines, are Space Marines who serve the Chaos Gods. They are also referred to as the Traitor Legions, primarily in background material written from the perspective of the Imperium.
The background shown in both Codex: Space Marines (Haines and McNeill, 2004) and Codex: Chaos Space Marines (Chambers et al., 2002) states that the Chaos Marine Legions were nine of the twenty Legions of Space Marines who fought in the Great Crusade for the Imperium of Man. At this time the Warmaster Horus, first among the Primarchs, and the Luna Wolves Legion (later the "Sons of Horus") were corrupted by Chaos and instigated the galaxy-wide civil war known as the Horus Heresy.
Further background to the Chaos Space Marines is explored in detail in the 'Horus Heresy' series of novels. After the death of Horus and the end of the Heresy, the remnants of the nine Legions along with the other Imperial forces that had joined Horus escaped to a warp-infested area of the galaxy connected directly to the Immaterium that is known as the Eye of Terror. Due to the nature of Chaos, and the temporal instability of the Warp, the very same Chaos Marines who revolted against the Emperor continue to fight against the Imperium.
The Legions have kept their old names, with the exception of the Sons of Horus who were renamed the Black Legion by their new leader, Abaddon the Despoiler. Besides Horus, two other Chaos Primarchs were believed to have been killed during or shortly after the Heresy (Konrad Curze of the Night Lords and Alpharius of the Alpha Legion.) The seven surviving Primarchs have since become Daemon Princes. These daemonic Primarchs rarely take part in the affairs of their Legions or any part of the Warhammer 40,000 universe. For example, Magnus the Red, Primarch of the Thousand Sons is the most powerful of all the Daemon Prince sorcerers. Yet he rarely enters the battlefield, even though prior to the Horus Heresy he always took part in his Legion's battles and was a determined warrior. Angron however, Primarch of the World Eaters, led an invasion force in what was to become the First War of Armageddon. Some of the Legions have pledged a particular loyalty to one of the four Great Chaos powers but the eight Blood Lords are loyal to Angron alone. The same is the case with the Death Guard, where the Primarch Mortarion's war council is known as the Lords of Decay. Abaddon the Despoiler has taken charge of the Sons of Horus, now known as the Black Legion. Abaddon is the only Chaos Marine since Horus to be able to command the loyalty of all nine Traitor Legions (albeit, temporarily after intense bargaining), and has led thirteen Black Crusades against the Imperium of Man.
A Black Crusade is composed of all the mustered forces of Chaos, from traitor space marine legions to heretical imperial citizens. It is believed to be the one true path to gain the favor of the Chaos Gods. A Black Crusade can be dedicated to a particular Chaos God in order to invoke their blessing and appease the Warmaster's or the heretics' patron. However, one should be careful in dedicating a Black Crusade to a particular Chaos God or multiple Chaos Gods as the Gods are protective of their champions' achievements and jealous of each other. Since M32 (the 32nd Millennium), there have been a total of 13 Black Crusades.
- 13th Black Crusade: Arguably, the thirteenth Black Crusade is the most (if not only totally) successful Black Crusade yet, with others believing that it signals the end times for the Warhammer universe. It began during the year 999 of M41, when multiple sightings of space hulks were reported. Abaddon the Despoiler (the Warmaster of the 13th Black Crusade) raises a vast armada from the depths of the immaterium, and initiates the largest clash between Imperial and Chaos forces since the Horus Heresy. In the end, this calamity resulted in massive casualties on both sides, with the forces of Chaos prying the powerful fortress world of Cadia out of the hands of the Imperium, a feat that had never succeeded before. Cadia is known as having the only known stable warp-route out of the Eye of Terror, and in addition to its substantial imperial military presence also contains the Cadian pylons- massive structures that are responsible (unbeknownst to the Imperium until the 13th Black Crusade) for restricting the Eye of Terror's growth. These artifacts are revealed to have been built by the Necrons, and were thus strategically critical for Abaddon's forces if the crusade was to make any meaningful headway. During the final battle on Cadia, Abaddon commands that a blackstone fortress (an ancient Xenos space station that predates the Imperium, possibly even created by the Old Ones) is flung to the surface of the world, destroying Cadia (and thus the Cadian pylons) and creating the Great Rift, known as the Cicatrix Maledictum by the Imperium, a massive galactic-scale dimensional tear in reality to the warp-which destroyed countless inhabited star systems. Social upheval in the wake of the Great Rift also means that virtually every world of the Imperium, even Terra, is engulfed by conflict. 
Forces of the Chaos Space Marines
Each of the Chaos Space Marine Legions specializes in a different type of warfare; each of the major Chaos Gods have a legion dedicated to them. The rules for the Chaos Space Marines are currently in their 8th edition, one of the few codices that have not been updated towards 7th edition (though both the Black Legion supplements and the Crimson Slaughter supplements have been updated).
The Chaos Space Marine Traitor Legions are as follows:
- Emperor's Children, once the III Legion of the twenty original Space Marine legions. Their primarch, Fulgrim, was dedicated towards the pursuit of perfection and was said to have given a speech so eloquent that his legion was given the honor of bearing the Emperor's Aquila as their symbol. During one of the Emperor's Children's missions against a xenos race called the Laer, Fulgrim was possessed by a daemon trapped within his sword. He later freed himself and joined Horus as leader of one of the original traitor legions. Driven by hubris and pride, the Emperor's Children later became devotees of the Chaos God Slaanesh, making extensive use of Noise Marines, armed with exotic Sonic Weaponry.
- Iron Warriors, once the IV Legion of the twenty original Space Marine legions. Their primarch, Perturabo, grew increasingly jealous of his brother primarchs, particular Rogal Dorn, primarch of the Imperial Fists. Specialists of siege warfare, they often came into conflict with the Imperial Fists, who also specialized in siege warfare. After a series of unrecognized, grueling attrition battles in which the Iron Warriors became more and more disillusioned, they turned to chaos and willingly joined Horus against their brother marines. After a series of civil wars, they have split apart into numerous warbands, with Perturabo himself achieving daemonhood and retiring to Medrengard, his personal planet filled with large metal fortresses belching smoke and fire. They possess a large number of daemon engines and Obliterators, hulking monstrosities of flesh and metal who can create any weapon they desire from their bodies.
- Night Lords, once the VIII Legion of the twenty original Space Marine legions. Their primarch, Konrad Curze (more commonly known as Night Haunter), grew up in the dark world of Nostramo, and took power of the planet's populace by executing and flaying all the criminals that stood in his way. The Night Lords became the most terrifying of the Space Marine legions; whole rebellious worlds surrendered at the knowledge of their arrival. Their primarch was also cursed with multiple visions, including one foreshadowing his own death, thus leading him further into insanity. After discovering that his homeworld had returned to anarchy after his campaign of terror to pacify them along with the fact that the Nostroman psychopaths who replaced the legion's losses were polluting the Night Lords, he ordered the destruction of his homeworld before fleeing to join Horus. After the Horus Heresy, he allowed himself to be killed by an Imperial assassin, wanting to prove that even the Emperor was willing to resort to such dishonorable actions. Unknown to the rest of his legion, Curze secretly despised his own legion, as they were made up of murderers and killers. The Night Lords currently are a united group of marines specializing in terror attacks, and so possess a large number of Raptors, chaotic versions of jet pack equipped assault marines.
- World Eaters, once the XII Legion of the twenty original Space Marine legions. Their primarch, Angron, grew up in the gladiator pits of Nuceria, and plotted a mass rebellion against the planet's rulers. The Emperor rescued him at the last moment, however, leading to his army's destruction and a deep rooted resentment of the Emperor for denying him an honorable battle alongside his gladiator brethren. Refusing to accept his legion, he killed the first seven captains before the eighth, Kharn, managed to earn his respect. Christened the World Eaters, Angron's legion was known for their relentless savagery in battle. Having been under Imperial pressure and already bloodthirsty thanks to the mental implants known as the Butcher's Nails, they willingly joined Horus and partook in his rebellion against the emperor. The legion's unity was shattered when their Champion Kharn attacked his comrades in a rage for accepting a ceasefire with another Chaos Legion during a civil war, leading to infighting that caused them to split into smaller warbands. Angron later achieved daemonhood, and currently resides in the Warp. The World Eaters now are devoted to the Chaos God Khorne, boasting more Khornate Bezerkers than any other legion.
- Death Guard, once the XIV Legion of the twenty original Space Marine legions. Their primarch, Mortarion, was raised by a warlord on a planet filled with noxious fumes, before rebelling against his adoptive father and finding solace with the enslaved populace of the planet. Having been saved by the Emperor from the warlord and denying him his chance to kill him, Mortarion gained a legion who specialized in biological warfare. Having been disillusioned by the Emperor's goals and believing him nothing more than a drunken tyrant, he was brought into Horus's rebellion and joined Horus as one of the four original legions who betrayed the Emperor. Known for their incredible fortitude, the Death Guard fought across the most noxious and hazardous war zones unscathed. Having been tricked by Typhus, the First Captain, into the Warp and besieged by plagues from all sides, Mortarion swore devotion to the Chaos God Nurgle and the Death Guard became fully swollen with disease and death. Having achieved daemonhood later on in history, Mortarion retreated to the Plague Planet which he now spends his time creating new plagues for his master. The Death Guard is composed largely of Plague Marines, specialists in biological warfare and disease.
- Thousand Sons, once the XV Legion of the twenty original Space Marine legions. Their primarch, Magnus the Red, was distrusted by all the other Space Marine legions, in particular the Space Wolves, because of their frequent use of magic and the powers of the Warp. Upon learning of Horus' corruption, Magnus sought to warn the Emperor with forbidden warp powers; only to unknowingly breach the Emperor's secret Webway portal Project. To make things worse, the Emperor refused to believe Horus turned traitor and sent the Space Wolves to apprehend the Thousand Sons for trial. Unfortunately, the Space Wolves were tricked by Horus into purging the Thousand Sons on their homeworld of Prospero. With his cities burning and his soldiers being slaughtered, Magnus had no choice but to swear fealty to the Chaos God Tzeentch, escaping into the Warp. Because of their frequent use of the Warp's magical energies, the Thousand Sons were cursed with frequent mutations, thus they historically numbered usually no more than a thousand Space Marines before Magnus' arrival. After a period of stability due to Magnus' use of warp powers, the mutations returned tenfold after turning to Chaos. In order to stop these mutations, their chief librarian Azhek Ahriman secretly cast a powerful spell which stopped the mutations while enhancing the powers of all psychic marines. However, the spell inadvertently turned the non-psychic marines into dust and bound their souls inside their Power Armors; reducing them to semi-distant automatons known as Rubric Marines. Of all Chaos Space Marine legions the Thousand Sons possesses by far the most Chaos Sorcerers.
- Black Legion, once the XVI Legion of the twenty original Space Marine legions. Formerly the Luna Wolves, their primarch, Horus Lupercal, was the first primarch discovered by the Emperor and was raised alongside his birth father, becoming the Emperor's most trusted primarch. After all the other primarchs were discovered, Horus was named the Warmaster and was granted command of all the Space Marine legions. He renamed his own legion the Sons of Horus, but a twinge of doubt existed in him as the Emperor kept secrets from Horus regarding the reason why the Emperor left the Great Crusade. After an accident which resulted in the Word Bearers manipulating Horus to fall under Chaos's sway, Horus openly declared a rebellion against the Emperor, instigating the Horus Heresy. After a series of attacks, most notably the purging of loyalists from the traitor legions on Isstvaan III and the decimation of the loyalist legions on Isstvaan V, Horus finally faced off against his father on the Emperor's warship, and was killed by the Emperor. In shame, the Sons of Horus painted their armor Black, renamed themselves the Black Legion, and fled back into the warp. Now Ezekyle Abaddon, the First Captain of the Sons of Horus, has sought to reunite all the forces of chaos under him in a bid to destroy the Imperium, christening himself the Despoiler. He has launched thirteen Black Crusades against the Imperium, the most recent being the setting of the current 40K universe. The Black Legion is also the largest and most infamous of the Chaos warbands, and quite possibly the most powerful.
- Word Bearers, once the XVII Legion of the twenty original Space Marine legions. Their primarch, Lorgar Aurelian, venerated the Emperor as a god, but was censured and made example of because the Emperor rejected religious superstition through the "Imperial Truth". Having grown disillusioned, Lorgar ventured into the Warp to seek new gods to believe in, discovering new masters in the Chaos Gods-who claimed they were vital to humanity's survival, and became the first legion to fall to Chaos. They orchestrated Horus's corruption and the entire Horus Heresy. Lorgar himself later achieved daemonhood, and the Word Bearers fractured after the end of the Heresy. Currently they make extensive use of daemons and possessed Space Marines, and also have a lot of Dark Apostles, priests who guide the members of the Word Bearers further in to the veneration of the Chaos Gods.
- Alpha Legion, once the XX Legion of the twenty original Space Marine legions. The last primarch to be discovered, Alpharius had a secret unknown to everyone: he actually had a twin named Omegon. The Alpha Legion was primarily used for secret missions, as they were known for their use of deception and subterfuge. It is said that after being revealed the future by an alien race, Alpharius joined Horus in his betrayal of the Emperor as a secret bid to finally eradicate Chaos from the universe. After the Heresy one of the two primarchs was said to have been killed by Guilliman, the primarch of the Ultramarines, while another may have been secretly killed by Rogal Dorn on Pluto. However, knowing the Alpha Legion's frequent lies and dissent, no one knows if one of them really survived or whether both survived. The Legion frequently uses Chaos Cultists for infiltration and sabotage, spreading throughout the universe in a web of lies and deceit.
Alongside the Traitor Legions, there have been many Space Marine Successor Chapters who have also fallen under the sway of Chaos. Some of the most notable ones are as follows:
- Red Corsairs, once the Astral Claws, their chapter master Lufgt Huron, powerhungry and seeking to create a legion sized force of Astartes, led several other chapters in a rebellion against the Imperial after the Heresy into what would later been known as the infamous Badab War. After being injured and nearly killed, Huron fled to the Warp alongside his chapter and were rechristened the Red Corsairs, with their leader becoming Huron Blackheart, the Tyrant of Badab. The Red Corsairs have amassed a massive pirate fleet, becoming a force to be reckoned with, rivaling that of the ancient traitor legions.
- Crimson Slaughter, once the Crimson Sabres, their chapter master Sevastus Kranon led their chapter on a crusade in the Warp, severing all connections with other Space Marine chapters though remaining loyal to the Imperium. After a massacre on Umidia however, the chapter was cursed by the Chaos God Khorne and forced to suffer painful hallucinations of all the people they killed. Driven mad by these unending visions, the Crimson Sabres found a moment of peace in their minds when conducting genocides. Forsaking the Imperium and renaming themselves the Crimson Slaughter, this warband is featured in Warhammer 40,000's starter set, Dark Vengeance, led by the Chaos Lord Kranon the Relentless.
- The Forsaken. In an event that will be known as the Abyssal Crusade, thirty Space Marine chapters were sent into the Warp on a mission under the influence of an Imperial Saint named Basillius (later revealed to be a Chaos worshiper and executed), and only one managed to return loyally the Imperium. The rest of these chapters became Chaos warbands or were completely killed. Some notable warbands are the Death Shadows, the Iconoclasts, and the Vectors of Pox.
The legions are often featured in short stories and novels published by Games Workshop's publishing arm, The Black Library.
Since the Horus Heresy, many Space Marine Chapters have been corrupted in one way or another by Chaos. No specific rules exist for renegade chapters, allowing players to adapt other rules to represent their forces. According to the records of the Ordo Malleus (the Inquisition branch body responsible for protecting the Imperium from Chaos and daemons), approximately 50 chapters have turned renegade after the Horus Heresy; however, the accuracy of this number is doubtful. Examples of given Space Marine chapters include the Sons of Malice, the Damned Company of Lord Caustos, the Violators, the Steel Cobras, the Thunder Barons, the Sons of Vengeance, the Silver Guards, etc. Beside those chapters the forces of chaos are also strengthened by individual corrupted companies or detachments from loyalalist Space Marine chapters; forming smaller warbands or joining other renegade chapters.
Differences between Chaos Space Marines and Space Marines
The Chaos Space Marines have the same origins as the Space Marines. Due to their allegiance to Chaos, Chaos Marines can be mutated or willingly possessed (except for the Thousand Sons Rubric Marines), thus making themselves into monsters, faster or otherwise superior to the Space Marines and other inhabitants of the Warhammer 40k universe. Chaos Marines have extended lifespans due to the time-warping effects of the Eye of Terror, and the fact that space marines as a whole are unable to die of old age, and their millennia of experience gives them levels of mastery with more advanced skills and tactics that Loyalist Space Marines do not have. However, they are inhibited by their own anarchic nature, limited numbers, and constant infighting. If they were to organize and form an army equivalent to the tactical army of the Imperium, they would be a greater threat than they are now. Abaddon of the Black Legion seeks to unite all of the Chaos forces and lead them to a last Black Crusade against the Imperium.
However, due to the hostility of chaos space marines toward each other, other legions and warbands, it took Abaddon 13 Black Crusades to finally cause significant damage towards the Imperium by launching a full-scale attack and occupation of Cadia.
Chaos Marines are equipped with the power armour and weapons they had when they initially betrayed the Imperium, which are broadly the same as those used by Space Marines (although some differences now exist). The current setting of the Warhammer 40,000 game is about 10,000 years after the Horus Heresy, and, while the Imperium has made some technological advancements, Chaos Marines have far more limited access to the handful of new inventions that have appeared on the galactic scene. For example, Iron Warriors are known for capturing and using Imperial tanks. This is not a strong differentiating factor though, as the Imperium merely replicates or rediscovers technology designed during the "Golden Age of Technology" (also known as the "Dark Age of Technology") and has very little understanding of it; thus there have been very few developments during the last 10,000 years.
- The death metal band Debauchery released several tracks/albums with references to the World Eaters. Most notable is the track "KILL MAIM BURN!".
- The British death metal band Bolt Thrower released a song titled "World Eater" on their album Realm of Chaos. The entire album is, in fact, themed around the Warhammer 40,000 concept of Chaos, as evidenced by the Games Workshop-produced artwork of the original printing, and song titles such as "Plague Bearer", "Dark Millennium", and "Through The Eye Of Terror".
- American Doom Metal band Cirith Ungol released the songs "Chaos Rising" and "Join the Legion" on their 1991 album Paradise Lost.
Parallel to realspace, where mortal creatures live, is the Warp, a realm of pure psychic energy. This realm is influenced by the thoughts, emotions, and urges of all sentient beings. The psychic energies sometimes coalesce into sentient entities. The most powerful of these entities are the four Chaos Gods. They are served by a host of daemons and constantly seek to expand their influence over humanity. In essence, the mortals of the galaxy are molested by monsters spawned by their own collective id. Though they are often at odds with each other, the Chaos Gods' common goal is to crush the worship of the God-Emperor and convert all of humanity to their cult. Chaos is the root of much of the universe's problems.
Chaos is a malevolent force that twists the bodies and minds of mortals exposed to it. Followers of Chaos are often lunatics who sport hideous mutations. Many humans worship the Chaos Gods in the hopes of alleviating their misery, advancing their ambitions, or gaining access to magical power, perhaps not understanding the terrible price they will ultimately pay. By far the people most vulnerable to Chaos influence are those with psychic ability. Unless they are carefully trained to resist daemonic possession, psykers can become living conduits by which daemons can enter the mortal world and wreak havoc.
There are no "good" gods in Warhammer 40,000, or at the least the good ones are greatly weakened, if not completely destroyed. The God-Emperor barely survives in a persistent vegetative state after a terrible battle with his son Horus who was corrupted by Chaos, and he is powerless to remedy the brutality, corruption, and ignorance that plagues his empire. After the Eldar gave birth to Slaanesh, their pantheon are all either dead or can do little to help their beleaguered people: most were killed by Slaanesh shortly after its birth, Cegorach (the Laughing God, an archetypical trickster) and Khaine (god of war and bloodshed) both fled, Isha (The Eldar Goddess of Fertility, Life, Healing and Growth) is captured by Slaanesh, and later "rescued" by Nurgle. Since she is captured by Nurgle and fed the diseases he concocts, the best she can do is whisper the cures for his diseases into the material universe. The Necrons were cursed to undeath by their gods, and eventually rebelled against them. The Ork deities are as anarchic, violent and cruel as they are, while the Tau and Tyranids have none at all.
Positive human feelings like love, altruism, valor, and invention are perverted by the Chaos Gods. For instance, Nurgle might represent acceptance and mercy, as he genuinely adores his worshippers and considers his plagues to be blessings. Tzeentch represents innovation and change, and a human who delves in science, invention, or social change risks becoming corrupted and mutated by his influence. Khorne thrives on violence of any sort, including that used by the Imperium to fight his own cultists.
Chaos is the root cause of most of the galaxy's problems. While Slaanesh gestated in the Warp, widespread warp storms cut off interstellar travel, leading to the collapse of the glorious human civilizations of old. When Slaanesh was finally born, the psychic shockwave slaughtered most of the Eldar race, leaving a tiny fraction of nomadic survivors. The Emperor of Mankind tried to reunite humanity, to bring it into a new golden age, but the Chaos Gods seduced and corrupted roughly half his Space Marine followers in an event known as the Horus Heresy and he was felled in battle, and his empire plunged into a dark age that has endured for 10,000 years.
Warhammer Age of Sigmar
Chaos stems from the Realm of Chaos, a mysterious dimension of raw magical energy and the home of the four Chaos Gods. Long ago, massive amounts of raw Chaos energy spilled forth into the world, its mutating power giving rise to many monsters such as trolls and the Skaven. Most forms of magic practiced by wizards use some form of refined Chaos energy, which are classified as the Winds of Magic. For instance, when Chaos energy filters through the natural world, it transforms into the Green Wind of Magic, which Jade Wizards and Druids can use for healing spells. Jade Wizards are at their most powerful wherever life is most abundant, and at their weakest where life is sparse (deserts, winter, etc.). Dark Magic makes use of unrefined Chaos energy and is thus the most dangerous.
- Warhammer 1st Edition
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- Index Astartes: Emperor's Children, White Dwarf 255