- "The world burned. Buildings blazed and toppled. A pall of soot and smoke hung over everything as the sun hid its face from the slaughter. All was fire, and the heat was like that of the desert. Presiding over the carnage like renegade gods were the Titans. Huge Warlords incinerated hundreds with fusion fire. They loomed out of the smoke of battle and where they walked there was destruction."
The Traitor Titan Legions are those units of the Collegia Titanica that repudiated their oaths of loyalty to the Emperor of Mankind and willingly embraced the fickle blessing of the Chaos Gods. Driven by hatred towards the False Emperor and the Adeptus Mechanicus, these towering, warped monstrosities are now an horror to behold, possessing an immense firepower that can only be matched by their Loyalist counterparts, and an insanity that allows them to happily partake in indiscriminate slaughter. They are a part of the Dark Mechanicus, and those Hereteks maintain these terror-inspiring war machines and offer their aid to various Chaos Lords, Chaos Sorcerers and Daemon Princes in exchange for slaves, souls, raw materiel and other services.
The Traitor Titans are often warped and mutated beyond recognition, their once-noble and resplendent figures, revered for their connection to the Machine God's divinity, turned into a cruel, menacing mockery of their former selves. Now they are entirely corrupted, their forms twisted by the powers of the Warp, their Machine Spirits replaced by possessing daemons and their crews' minds driven to madness by endless torment -- traits that only serve to mold them into even more fearsome adversaries.
The Adeptus Mechanicus harbour a deep-seated hatred of the Traitor Titans, particularly of their crews, as their actions have damned the once-divine machines, something that the Tech-priests hold as a great sacrilege. This enmity is entirely mutual, as the loathing the Traitor Titans have for the Mechanicus of Mars and the Collegia Titanica may very well exceed the rancour felt towards the Emperor Himself.
Most of the Traitor Titan Legions turned to Chaos during the Horus Heresy, when Titan elements attached to the Expeditionary Fleets of the Space Marine Legions decided to support the Warmaster cause by virtue of their devotion to Horus and their commanding Primarchs, and because of their fading loyalty towards the distant Emperor. Other Legions supported the Heresy on Mars due to their affiliation with the subversive schemes of the Fabricator-General Kelbor-Hal and the Dark Mechanicus, who were increasingly ambivalent towards the Imperium and the unfulfilled provisions of the Treaty of Mars. Not all these seditions, however, occurred as a direct result of Horus' ferment, as Titan Legions are known to have fallen to Chaos long after the Horus Heresy ended. Regardless of the reasons for betrayal, each and every time a Titan Legion or individual Titan has been lost to the Ruinous Powers, it represents a distinct threat to the Imperium, as well as a stain on the Collegia Titanica's honour. And this is a stain that can only be washed away by the blood of the Traitors.
At the height of the Great Crusade in the early 31st Millennium, the Warmaster Horus came under the sway of the Ruinous Powers and began to plan his betrayal. When the first fratricidal shots were fired, those members of the Collegia Titanica that would become known as the Traitor Titan Legions had already chosen their sides and eagerly engaged in the internecine conflict that would change the galaxy and the Imperium for millennia to come.
The Traitor Titans aided Horus' forces from the beginning of the revolt against the Emperor, most notably the infamous Legio Mortis which had battled the Traitor Legions' remaining Loyalist Astartes during the Battle of Istvaan III following the virus-bombing of the planet, and took part in the Drop Site Massacre on Istvaan V. Other Titan Legions that had been attached to the Expeditionary Fleets also sided with the Traitors, amongst them the Legio Argentum (who were attached to the Primarch Perturabo's forces), and the Legios Vulcanum, to name but a few.
Schism of Mars
The climate on Mars was full of discontent during this tumultuous time in the days just before Horus openly declared his rebellion against the Emperor. There were tense relations between the various Mechanicum Magi who governed Mars with sporadic outbreaks of espionage and violence being committed against the various forges that represented the primary sociopolitical units of Mars. There were even unconfirmed suspicions that the various Titan Legions of the Collegia Titanica, the most potent military forces available to the Tech-priests, had already secretly chosen sides in case of a potential conflict within the Mechanicum.
At the outset of the Heresy, Horus sent Regulus, the Mechanicum's representative to Horus' 63rd Expeditionary Fleet who had already thrown in his lot with the Warmaster's cause, to the Red Planet to secure the tentative support of the Fabricator-General of Mars and the overall leader of the Mechanicum, Kelbor-Hal. Regulus convinced the Fabricator-General of Horus' resolve to support increased autonomy for the Mechanicum against the autocratic rule of the Emperor. As a show of his appreciation for the Fabricator-General's support, Horus provided information to Kelbor-Hal that allowed the Mechanicum to open a repository of forbidden knowledge known as the Vaults of Moravec, which had been sealed for nearly a thousand standard years. The Emperor Himself had decreed that the vaults never be opened, for they contained innumerable artefacts of technology that had been fashioned or corrupted by the malign power of Chaos in ages past. But the deal was struck, and the Fabricator-General accepted Horus' proposal and joined forces with the Warmaster, assisting the Traitors with all of the most advanced technology of Mankind at his disposal.
Later histories would record that the first blow of the Martian civil war was struck against Magos Mattias Kefra, whose forge city in the Sinus Sabaeus region was housed within the Madler Crater. Titans of the Legio Magna marched from the southern Noachis region and within solar minutes had smashed down the gates of Kefra's forge. Howling war engines daubed in red, orange, yellow and black, decorated with flaming horned skull devices, ran amok within the high walls of the crater, crushing everything living beneath them and destroying thousands of standard years of accumulated wisdom in a fury of fire. Vast libraries burned and weapon shops that served the Imperial Army troops of the Solar Guard were reduced to molten slag as the indiscriminate slaughter continued long into the night, the Legio Magna 's trumpeting warhorns sounding like the atavistic screams of primitive savages.
Amid the Athabasca Valles, the war machines of the Legio Ignatum and the Burning Stars Titan Legion fought in bloody close quarters through the teardrop landforms caused by catastrophic flooding in an earlier, ancient age of the Red Planet. Neither force could gain the advantage, nor could either claim victory, so after a night's undignified scrapping, both withdrew to lick their wounds.
Along the borders of the Lunae Palus and Arcadia regions, what previously had been simply a heated debate between the partisans of the Emperor and Horus erupted into outright civil warfare as Princeps Ulriche of the Death Stalkers unleashed his war engines upon the fortress of Maxen Vledig's Legio Honorum. Caught by surprise, the Legio Honorum lost nineteen Titans in the first hour of battle, before withdrawing into the frozen wastes of the Mare Boreum and seeking refuge in the dune fields of Olympia Undae. Their calls for reinforcement went unanswered, for all of Mars was tearing itself apart as the plague of civil war spread across the planet in a raging firestorm, a conflict known as the Schism of Mars by later generations.
The Fabricator-General's betrayal had only begun to unfold, and would soon see the Dark Mechanicus and the Traitor Titans of Mars joining Horus in open war against the Emperor on Terra itself.
Battle of Terra
- "I saw an angel clad in crimson, descend within the winds on pinions of iron.
I saw an angel pale of skin, the seal of the fall still raw upon his brow.
I saw an angel wreathed in flames of every hue, words of power on his red lips.
I saw an angel who was death, return'd from the grave to call us.
And with each a host of engines, for where treads steel treads our doom."
- — Manifestations of the End Times, Verses XXII-XXVII, Vol. LXXXVII
The Siege of Terra by the Traitor forces of Horus began with an orbital bombardment by the Warmaster's fleet as the prelude to invasion. After days of shelling, the Astartes of the Traitor Legions landed on the surface of Terra in Drop Pods and advanced on the two spaceports nearest the location of the Imperial Palace to secure them in preparation for the main landings of the Traitor forces. Elements from five of the Traitor Legions participated in the battle, aided by Traitor forces already on the surface. Despite the brave efforts of the Loyalists, the Eternity Wall and the Lion's Gate Spaceports fell within solar hours to the Forces of Chaos. With them secured, Horus' remaining troops in the Traitor Legions and their Traitor Imperial Army and Dark Mechanicus support forces landed en masse, and the hulking transports carried thousands of troops each. They also brought to the battlefield the terrible Traitor Titans that served Horus' cause and had been infected with the daemonic spirits of Chaos. The transports' immense size made them prime targets for Terra's Defence Lasers. Although many of the Traitor landing craft were destroyed in-atmosphere, notably the transport vessel carrying the Legio Damnatus, many more made it to the surface, disgorging yet more soldiers, main battle tanks and Traitor Titans to add to the besiegers' strength. They met stiff resistance from the Loyalists as the Imperial defenders knew that the survival of their homeworld, their Emperor, and the entirety of the human race rested on their shoulders.
The siege of the Imperial Palace then began in earnest. Three times the Forces of Chaos scaled the walls, and three times were hurled back by the defenders. Frustrated at this lack of progress, Horus granted the Legio Mortis the singular honour of breaching the walls of the Imperial Palace, amongst whose defenders were the Loyalist Titans of the Collegia Titanica and their hated rivals -- the Legio Ignatum. Using the many powerful weapons at their disposal, they eagerly set about the task. By virtue of their insane fury they accomplished this near-suicidal endeavour, despite suffering the losses of over thirty Titans in one evening of fierce fighting. The Chaos Warlord-class Titans broke the outer walls and let inwards a flood of Traitors.
It was also during the Battle of Terra that the Traitor Warhound-class Titans, acting on Horus'orders, roamed the planet in packs and terrorised the civilian population. The massacres perpetrated by these murderous behemoths caused the High Lords of Terra, during the later reformation of the Imperium, to order the Collegia Titanica to never again allow Warhound-class Titans to operate in squads larger than two war machines, so that such horrors might never again be visited upon Mankind. Obviously, the Traitor Titan Legions do not feel bound by this rule.
Regardless of their efforts, Horus was ultimately laid low by the Emperor, and the remaining Traitor forces, facing defeat, hastily retreated from Terra and sought refuge in the Eye of Terror.
Following the failure to take the Imperial Palace on Terra, the Traitor Legions were driven to the Warp realities of the Eye of Terror after the Heresy. The Titan Legions that had followed the Warmaster's cause fled with them, and the price they paid for their treacheries was heavy indeed. The powers of Chaos were quick to bestow the full extent of their dark blessings upon these peerless machines of war, working upon them to make them more pleasing in their sight. The heads of some were reshaped into daemonic visages, or mounted with massive blades or cannon, while many grew long sinuous tails tipped with wrecking balls or still more cannon or blades.
From the Eye of Terror, as well as from other vantage points like the smaller Warp rift known as the Maelstrom, the Traitor Titan Legions continue to wage the Long War against the Emperor, taking part in raids on outlying Imperial worlds, supporting Black Crusades which strike out into Imperial-held space, as well as engaging in battles between the various Chaotic factions themselves. Though somewhat similar to their Imperial counterparts, their long exposure to the warping influence of Chaos has changed many of them. In some cases, the crew has merged with their machine, making it impossible to tell where one ends and the other begins. Other crews have given themselves and their weapons over solely to the service of one of the four great Ruinous Powers of Chaos. The Titan's Machine Spirit and its damned crew become possessed by daemons and are doomed to serve the will of the Chaos Gods in battle for all eternity. Yet Chaos can corrupt Titan Legions at any time, and the ranks of the Traitor Titan Legions have grown over the millennia since the Heresy. There are two known Titan Legions that have, much to the Collegia Titanica's eternal shame, repudiated their oaths of fealty to the Emperor and willingly betrayed Mankind in recent times -- the Legio Lacrymea and the Adamant Fury Legion.
- Siege of Vraks (813-830.M41) - The Siege of Vraks was an Imperial military campaign fought over the course of 17 standard years to retake the Imperial Armoury World of Vraks Prime from the heretical Forces of Chaos led by the Apostate Cardinal-Astra Xaphan of the Scarus Sector. Vraks was besieged by the forces of the Imperium of Man in 813.M41, after the attempted assassination by an agent of the Officio Assassinorum of the heretical and traitorous Xaphan. The Imperial Guard's 88th Siege Army was raised from line regiments of the Death Korps of Krieg to undertake the Siege of Vraks and bring the Renegade Cardinal down in a campaign of attrition that the Administratum's Adepts calculated would take 12 standard years to successfully conclude. At the conclusion of what became a 17-year-long campaign of attrition requiring 34 regiments of the Imperial Guard to re-take the planet for the Emperor of Mankind in 830.M41, 14 million Imperial Guardsmen had been lost and Vraks Prime's entire original population of 8 million souls had been consumed in the violence or exterminated after they fell to Chaos corruption. This campaign was, amongst other things, a prime example of the deployment of Traitor Titan Legions in support of Heretic forces in the 41st Millennium, as well as a clear display of their value to the Forces of Chaos. The Traitor Titans sought to arrive on Vraks along with the other Forces of Chaos on the transport vessel Aharon's Bane. Although the Imperial Navy managed to damage the ship, the vessel survived planetfall and crashed west of the Chaylia Plateau, tearing a great gouge into the surface of Vraks and leaving its remains scattered across kilometres of the planet's surface. The Imperial naval force's commanders had hoped that the damage inflicted would see the craft destroyed, but this was not to be. Although many died as a result of the landing, far more survived, and warbands disgorged from the ship's ravaged hull were soon preparing for battle -- amongst them the dreaded Titans of the Legio Vulcanum I. From there, the Chaotic reinforcements moved to engage the Imperial Guard corps besieging the defensive lines surrounding the Citadel of Vraks. The Titans soon proved their worth once they engaged the Imperial forces of the 101st Death Korps of Krieg Regiment, opening fire at long range and devastating the Krieg armoured columns sent to face the Traitor onslaught. Clouds of brown dust stirred by the advancing tanks turned to blue-black smoke as the vehicles were smitten by the fury of Turbo-Lasers, Gatling Blasters and Volcano Cannons mounted on the massive war machines. The attempts to retaliate were all for naught, as the armour-piercing shells deflected off the Titans' Void Shields with electric blue flashes. Even repeated blasts of an Imperial Shadowsword super-heavy tank's mighty ordnance flickered harmlessly off the Titans' shields. For all its efforts, in response the great tank was disarmed by a single shot of a Turbo-Laser, and its crew immolated by a successive blast. Ultimately, the Imperial force sent to halt the Heretics' reinforcements failed. The defeat of the 101st Krieg Regiment meant that the Death Korps could no longer maintain a ring surrounding the fortress. The 19th Krieg Regiment had been ordered to relocate and face this grim threat alone to buy the time needed by Imperial forces sieging the eastern side of the fortress to abandon posts and move to a defensible position. These manouvres would see the regiment cut off. In such circumstances, the 19th could not have hoped to last long, especially if the Archenemy made use of their Titans. Such desperate measures were required just to save the Imperial campaign from complete failure. These defeats prompted the commanding Lord Militant Obscurus to replace the 88th Siege Army's command staff. The Imperial Guard officer eventually chosen for this task was Marshal Arnim Kagori. His first action, after assembling his staff, was to gather help for the beleaguered Krieg regiments on Vraks. In addition to securing the aerial support of the Imperial Navy and more manpower from Krieg, Kagori sought to be able to counter enemy Titans, and to this end petitioned the Legio Astorum -- the Warp Runners -- for help. The venerable lords of Lucius, the Legio Astorum's home Forge World, agreed. A battlegroup of Titans was deployed to support the 88th Siege Army, as only they could hope to match the firepower of the Traitor Titans. After their rites of battle were complete, they embarked upon their transport vessels and set off for Vraks. Soon, Kagori's reinforcements arrived on the planet, and amongst them was the Legio Astorum battlegroup, comprising 10 Reaver-class Titans and 12 Warhound-class Titans led by the venerable High Princeps Rand Drauca, ready to face the Traitors on the battlefield and resume the war that had been ongoing for ten thousand standard years. The Warp Runners supported the Marshal's new offensive to great effect, and very soon the Legio Vulcanum I took to the field to face them. Both sides were initially evenly matched, and the Legio Astorum suffered its first loss of the campaign -- the Reaver-class Titan Invigila Alpha. The Vraksian Renegades were heavily battered by Kagori's fresh forces, and were only able to hold the tide owing to the assistance of the Traitor Titans. However, as the fighting progressed, the Legio Vulcanum I found itself outmatched by its Collegia Titanica counterparts, and was eventually forced to pull back and regroup after -- according to the Warp Runners -- losing 12 war machines, a feat for which the Legio Astorum paid with the disabling of 11 of its own Loyalist Titans. The Titans clashed once more at the Red Scorpions Space Marine Chapter's first landing site. The Space Marines arrived on Vraks heeding Marshal Kagori's plea for aid following the Departmento Munitorum's unfavourable review of the campaign and its subsequent downgrading in reinforcement and resupply priority. The Red Scorpions opted to descend upon the planet's surface into the breach located in Sector 57-44, where they deemed their assistance would be put to best effect. A plan was agreed upon, which would see a special battlegroup from the 88th Siege Army's 11th Assault Korps supported by Legio Astorum Titans exploiting the breach once the Red Scorpions succeeded in securing the area. The enemy had contingency plans for assaults on the breach, and moments after the Space Marines' arrived they were already fighting the forces of the swarming Heretics, including Traitor Titans. Guardsmen rushed to aid the beleaguered Red Scorpions and trailing behind them were the Warp Runners, who eagerly engaged the Legio Vulcanum I, seeking to repeat their previous success. The great war machines engaged in vicious duels as the fighting continued around them, and despite suffering the loss of even more machines, the Legio Astorum triumphed, forcing the Traitor Titans to retreat. High Princeps Rand Drauca could celebrate another victory over the despised Legio Vulcanum I on his Titan's honour banner. Imperial records bear no mention of further actions undertaken by the Traitor Titans on the battlefield, though, it can be presumed that they continued the fight, as they are known to have defended the Citadel of Vraks itself. The number of Titans deployed by the Traitors on Vraks is unknown, although the Legio Astorum claims to having destroyed fourteen, losing nine of theirs in the process. If this is true, then the Legio Vulcanum I paid a heavy price for their involvement. How the remaining Traitor war machines -- if there were any -- escaped from Vraks following the eventual Imperial victory is also unknown. Of the Legio Vulcanum I's actions during the campaign perhaps only one thing is certain -- they sowed destruction and terror wherever they went.
Due to the very nature of Chaos, the united force that Horus commanded during the Heresy split into bickering and warring factions following the Great Scouring. This was also the case with the Hereteks and Traitor Titan Legions of the Dark Mechanicus who supported the Warmaster. They took residence on a number of Dark Forge Worlds and divided themselves into different sects and cults, each pursuing their Quest for Knowledge in fields and ways which they deemed most appropriate. The Traitor Titan Legions did not have the same liberty to serve the Ruinous Powers as the other Forces of Chaos did. As the Traitor Titans became warped into forms more pleasing to their new masters and possessed by daemons, they were still at least partly machines, and thus required the tending and maintenance only the Hereteks could provide, as well as ammunition produced by slaves on Dark Forge Worlds. Because of these logistical realities, the Traitor Titan Legions are invariably tied to the Dark Mechanicus and are effectively at their command. They protect the Dark Forge Worlds, aid the Hereteks in their expeditions searching for archeotech and in essence act as mercenaries whose services can be obtained by various Chaos Lords, Chaos Sorcerers and Daemon Princes in exchange for slaves, souls and raw materiel granted to the Dark Tech-priests.
Many of these war machines are ancient and irreplacable relics of the Horus Heresy, and although the Hereteks supply the Legions with new machines crafted in their hell forges, these are not always enough to replace the battlefield losses they sustain. However, the Traitors can replenish their numbers in other ways. One of them, predictably, is betrayal. Some Titan Legions of the Collegia Titanica are known to have embraced the blessings of Chaos long after the Horus Heresy, and it is likely that such occurrences are more common, but all notions of them are struck from Imperial records. Dark Mechanicus Tech-priests also seek to salvage Loyalist Titans from the battlefield, repair them and subject them to bloody rituals in order to consecrate them in the service of Chaos whenever possible, much to the shame and outrage of their former masters and the Cult of Mars. The number of Traitor Titan Legions and the number of Traitor Titans remaining to them is unknown, however, bearing in mind that at the outset of the Horus Heresy fully half of the Collegia Titanica declared for Horus, and considering the fact that the Adeptus Titanicus currently deploys over 100 Titan Legions to watch over the Eye of Terror alone, one can estimate the figures to be significant.
In many cases, the fate of the Titans' crew that entered the Eye of Terror was a dark one. Once, Titans were controlled by their crew -- the Princeps, Moderatii, Tech-priests and Servitors -- via a hard-wired Mind Impulse Unit that translated every thought into a concomitant deed by the Titan. Having turned to the service of the Ruinous Powers, these crews are now possessed by daemons, as one flesh with the God-Engine, their bodies and souls sacrificed on the altar of battle and merged in eternal damnation. They are destined to battle forever for the pleasure of their baleful gods and are driven to ever-greater depths of destruction by the ceaseless hatred they bear for those they once called brothers. Not all Princeps succumbed to madness and possession, however, for a few have ascended to a new tier of existence entirely. These are the incarnate avatars of the Ruinous Powers, wielding their God-Machines as an extension of their own bodies and lording over the puny creatures that crawl upon the ground at their feet. They are the tyrants of worlds, yet the concerns of kings and rulers are not theirs. They care only for bloodshed and conquest, and will never rest until all the worlds of the Imperium are crushed beneath their tread.
Other Titans are presumed to be operated by the daemons which possess them, their original crews either dead or now possessed themselves. This occurs most commonly when Greater Daemons fuse with an Imperator-class Titan, transforming these great war engines into towering leviathans of Warp-corrupted steel and Adamantium, a true incarnation of the power of Chaos in the material realm.
Weapons of Damnation
Chaos Titans carry weapons of awesome firepower capable of laying waste to vast swathes of the battlefield and slaying enemies by the score. Scout Titans such as the Warhound generally carry two weapons, one on each shoulder mounting point, and these are almost always ranged weapons, for their role is to locate enemy ground forces and harass enemy Scout Titans rather than to launch close assaults against other Titans. The larger Battle Titans, such as the Reaver and the Warlord, mount a weapon at each shoulder and still more atop their armoured carapace. Battle Titans can be outfitted for a range of roles, and as such some are equipped with one or even two Titan close combat weapons, allowing them to engage rival Titans in apocalyptic duels that consume not just the defeated Titan, but potentially hundreds of troops unfortunate enough to be caught in its death throes. To witness such a fight to the death is to watch demigods of legend engaged in epic confrontation, the sight so awe-inspiring that entire armies of lesser mortals have on occasion been rendered senseless and mute by the spectacle, ceasing their own mutual struggle until it is concluded.
Many, though by no means all, Battle Titans carry a close combat weapon, often taking the form of a massive Power Fist or claw, but sometimes a mighty Chainsword able to slice a super-heavy tank in two in a single sweep. Being blessed by the Ruinous Powers, Chaos Titans are known to sport a range of less classifiable melee weapons, such as multi-headed flails, scourges and even huge, spiked wrecking balls at the end of enormous chains. There are numerous other classes of weapons, each optimised for a specific battlefield role and used in combinations defined by the nature of foe the Titan is to face. Multi-barrelled Laser Blasters fire intense beams of energy able to cut through the heaviest of armour in a single strike. Gatling Blasters fire a torrent of shells so dense they can tear entire formations of enemy vehicles to ragged scrap. Plasma Blastguns unleash the power of an exploding star in a blast so fierce even the most heavily armoured infantry are rendered to ash scattered to the winds. Melta Cannon are used to melt entire sections of fortress wall to molten slag, cooking alive any defenders foolish enough to remain within. The Inferno Cannon fires a cascade of ravening flame that sets entire battlefields alight and turns the skies black with ashen clouds, while their Apocalypse Missile Launchers blot out the sun with volley after volley of high explosive missiles so dense the result is a carpet of blossoming detonations that consumes the entire battlefield. Perhaps rarest and most potent of all are the Vortex Missiles, deployed only upon the orders of the very highest authority -- the Segmentum lords in the case of the Imperium, the most favoured warlords in the case of the servants of Chaos -- weapons that unleash the power of the Warp itself, creating a briefly-lived portal through which any foe can be sucked into, and from which none can ever return.
The Traitor Orders
Many Titan Legions -- or Orders as they are alternatively known -- can trace their legacy to the all but forgotten ages before even the Emperor untied humanity and founded the Imperium of Man. Very little is known outside of the sealed archives of the Adeptus Mechanicus, but some within the Inquisition hold the Titans were first conceived so that rival Martian fortress-foundries could protect themselves from one another and from the ravening mutant hordes that infested the red wastes of Mars during the dark millennia of the Age of Strife. If such claims are true, there is a grim irony in the fact that, even as the 41st Millennium draws to a close, these mighty "God-Machines" continue to wage war upon one another, unleashing weapons only accessible to the Tech-priests - or former Tech-priests - of the Martian Cult.
Each Titan Order was founded to defend one of the many Forge Worlds throughout the galaxy, though in truth not every Forge World had the requisite lore or resources to do so, while conversely, some were so blessed in this regard they could raise more than one Legion. As many Forge Worlds predate the Great Crusade, so many Orders have pasts so obscured by the passage of time their deeds during the Age of Strife are matters of legend to all but the most senior of Magi. Some orders were established as the Great Crusade swept ever outwards from Terra and the Mechanicum of old claimed ownership of those worlds that met their particular needs. Though expansion turned largely to stagnation during the Age of the Imperium, occasionally new Forge Worlds were founded, and some were able to raise their own Titan Legions in order to protect themselves and their interests against the numerous foes that haunt the void.
The majority of the Traitor Titan Legions fell to the service of the Ruinous Powers during the calamitous age of the Horus Heresy, though a few more have fallen in the ten millennia since. The causes of their fall were as varied as those of the Traitor Space Marine Legions, some being laid low by bitter hubris, others by malignant intent, and some by the vagaries of capricious fate. What accounts remain state that over half of the Titan Legions renounced their oaths to the Emperor and declared for the Warmaster Horus, and fought alongside the Traitors across the length and breadth of a galaxy torn apart by a civil war the likes of which had not been seen before.
The Traitor Titan Orders were to share in the damnation of the Traitor Legiones Astartes, and while their names might not be as well known or reviled as Traitor Legions such as the Sons of Horus, the World Eaters or the Death Guard, for many amongst the upper echelons they represent a force every bit as dangerous. Traitor Orders such as the Legio Fureans -- colloquially known as the "Tiger Eyes," the Legio Vulcanum I - so-called "Dark Fire," and the Legio Mortis -- the "Death's Heads" -- have caused untold devastation the length and breadth of the Imperium since the dark days of the Great Betrayal. Others have fallen since, including those known as the Adamant Fury and the Helldogs, suggesting to some that a new and unheralded doom is stalking the Imperium as the close of the 41st Millennium draws inexorably nearer and warriors once counted amongst the most loyal prove themselves nothing more than base betrayers. The annals of the Imperium list numerous other Traitor Orders, some not heard of for centuries and assumed extinct before returning to inflict death and misery upon the Imperium once more. Some are known only to legend -- such as the Death Stalkers and the Flaming Skulls -- but the wise refuse to count them as a spent force given the sheer number of foes arrayed against the Imperium of Man.
All Chaos Titans are towering effigies of blasphemy and terror, walking altars to the Ruinous Powers before which the bloodiest of sacrifices are made. Yet still there exists in the galaxy things even worse than this, a class of Titan so steeped in the corruption of the Warp that it has mutated into a Daemon Titan. These are the ultimate expressions of the corruption of the machine. Like all Titans, each was once a mechanism of steel and ceramite, controlled by a mortal Princeps and his Morderatii, and driven by a plasma reactor harnessing the power of a star. At some point, however, the touch of Chaos has so tainted the machine that it has been transformed into something else entirely. The savants and daemonologists of the Ordo Malleus know little of the true nature of the Daemon Titans, for to contemplate such things is to court damnation and madness, but all appear to agree on one thing -- Daemon Titans are driven not by the will of a mortal Princeps, but by that of a daemon called forth from the Sea of Souls, and a powerful one at that. Invested with an infernal malignance as potent as a Greater Daemon, Daemon Titans are relentless engines of destruction. Though clad in metal, they have no need of fuel or ammunition. The maintenance rituals required to keep other Chaos Titans operational are meaningless to such an engine of war, though they make other demands upon those who would call upon them to make war against the Imperium. It is said that in between battles, a Daemon Titan must be constantly supplicated with blood and blasphemy, its unholy thirst slaked by offerings of suffering and murder.
In battle, Daemon Titans are Chaos incarnate. Their eyes rage with the ravening madness of the Warp, the air about them distorting as reality itself is tortured by their presence in the mortal realm. Daemon Titans rarely heed the strategies of those who call upon them, fighting according to their own unknowable drives and desires. In truth, the daemon bound within the Titan's metal form appears concerned only that it reaps the highest possible toll of souls to the glory of those few powers higher than itself in the pantheon of the Warp. Of all the foes a Daemon Titan might encounter upon the field of battle, of all the deaths it might claim in the name of the Ruinous Powers, enemy Titans in the service of the God-Emperor of Mankind are sought above all others. Having sighted an Imperial Titan, there is little in the galaxy that can stop a Daemon Titan from engaging it, and woe betide any who stand in its path as it charges its foe, cannon blazing, Chainblade screaming, Power Fists crackling and a daemonic howl of savage rage stunning or even slaughtering all in the vicinity.
In appearance, a Daemon Titan might be taken for a gargantuan manifestation of a Greater Daemon of the same patron Ruinous Power and indeed, Ordo Malleus savants have debated the difference to, and sometimes beyond, the point of sanity in a vain effort to quantify the unfathomable permutations of Chaos. Those dedicated to Khorne are beasts of burning brass and steaming blood, their heads wrought into snarling beast faces. The Daemon Titans of Nurgle are lumbering masses of decay and corruption, metal tarnished and surrounded by a black storm cloud of plague flies so thick they foul enemy guns and vehicles, and force themselves down the throats of enemy troops. Daemon Titans dedicated to Tzeentch are clad in impossible colours and reality itself is bent out of kilter by the sorcerous power radiating from their form. Those dedicated to Slaanesh are lithe and incongruously fast, their forms surmounted by wicked blades and surrounded by a haze of psychoactive mist. These and a thousand other blasphemous manifestations of the infernal are a relentless curse upon the Imperium of Man, a curse that only intensifies as the 41st Millennium draws to a bloody conclusion.
- "Bow down before him, favoured of Chaos! Tremble at his footstep, and give praise for his slaughter."
- —Dark Magos Ulth'alix
Although the Chaos Titans are effectively subordinate to the Hereteks, the Dark Mechanicus do not view them as servants, but revere them, depending on the beliefs they hold, as the perfect amalgam of daemon and machine, a fusion of technology and the power of the Warp, or as the incarnations of the Machine God embodied in the power of Chaos Undivided. The latter is a perversion of the Adeptus Mechanicus beliefs concerning Titans as the avatars of the Machine God in realspace, and holds true for those Hereteks that have not scorned their faith in the Omnissiah.
Fittingly, many amongst the lesser servants of Chaos view these towering war engines as gods of fire and death in their own right, giving obeisance to them much as they would to the Greater Daemons. They are known to offer captives as sacrifice to the Chaos Titans, as well as their own lives to slake these behemoths' thirst for blood. On the battlefield they are always encouraged by the manifest presence of the power of Chaos represented by Chaos Titans and fight even more fiercely to prove their worth to the Ruinous Powers. There have been known instances where the mere presence of Traitor Titans on the field has kept Chaotic forces from routing and has emboldened them to hold the line and fight back.
Known Traitor Titan Legions
- Adamant Fury
- Burning Stars
- Festering Death
- Forsaken Reavers
- Iron Skulls
- Riotous Host
- Legio Abhorrax
- Legio Argentum (Dread Lances)
- Legio Audax (Ember Wolves)
- Legio Convenentia
- Legio Damnatus (Warped Dogs)
- Legio Damnosus (Lords of Ruin)
- Legio Excruciatus (Helldogs)
- Legio Frostreaver
- Legio Fureans (Tiger Eyes)
- Legio Interfector (Murder Lords)
- Legio Krytos (God Breakers)
- Legio Kydianos (Death Cry)
- Legio Lacrymea (Harbingers of Grief)
- Legio Magna (Flaming Skulls)
- Legio Metallum Armaturum
- Legio Mordaxis
- Legio Morbus
- Legio Mortis (Death's Heads)
- Legio Pestis
- Legio Proditor
- Legio Serpentes
- Legio Suturvora (Fire Masters)
- Legio Tempestor (Storm Lords)
- Legio Ulricon
- Legio Vendettica
- Legio Vulcanum I (Dark Fire)
- Legio Vulcanum II (Lords of Ruin)
- Legio Vulpa (Death Stalkers)
- Legio Vulturum (Gore Crows)
- Legio Xestobiax (Iron Vigil)
- Codex Heretic Astartes - Death Guard (8th Edition), pg. 23
- Citadel Journal 9, "Legions of Chaos: Bubonis, Daemonic Plague Titan of Nurgle" by James Funnell, pp. 4-11
- Citadel Journal 10, "Skylok, Winged Titan of Tzeentch", pp. 31-37
- Citadel Journal 13, "Abominatus, Despoiler of Worlds Chaos Titan", pp. 41-44
- Citadel Journal 27, "Dok Butcha's Klinik: Bitz N' Tipz - Conversions: Chaos Banelord Titan of Khorne", pp. 91-96
- Codex: Eye of Terror (3rd Edition), pg. 16
- Gathering Storm - Book II - Fracture of Biel-Tan (7th Edition), pg. 84, "Opticon Sol" Sidebar
- The Horus Heresy: Collected Visions by Alan Merett, pp. 354-362
- Titan Legions (1994), pp. 8, 12, 16, 39
- Imperial Armour Apocalypse (2nd Edition), pg. 104
- Imperial Armour Volume Six - The Siege of Vraks - Part Two, pp. 11-12, 23, 26-27, 34-35, 42-43, 48, 78-79, 83-84, 163, 182
- Imperial Armour Volume Seven - The Siege of Vraks - Part Three, pp. 51, 88, 161, 172
- Imperial Armour Volume Thirteen - War Machines of the Lost & The Damned, "Chaos Titans," pp. 136-146
- Warhammer 40,000: Rulebook (8th Edition), pp. 158-159
- Warhammer 40,000: Rulebook (5th Edition), pg. 127
- White Dwarf 267 (US), "A Clash of Titans: A battle report - Chaos vs Ulthwe Eldar"
- White Dwarf 194 (US), "Modelling Workshop: Abominatus, Despoiler of Worlds", pp. 39-43
- White Dwarf 190 (US), "Slaanesh War Machines: Chaos", pp. 27-34
- White Dwarf 188 (US), "Plague Engines of Nurgle: Chaos", pp. 23-26
- White Dwarf 180 (US), "Fists of Death: Titans Tactics", pp. 27-36
- White Dwarf 178 (US), "The Titan Legions: History", pp. 45-52
- White Dwarf 171 (US), "Chaos Armies: Chaos Titans", pp. 25-35
- White Dwarf 164 (US), "The Banelord: Chaos Titan of Khorne", pp. 21-25
- White Dwarf 142 (US), "Titan Weapons - Imperial Titan Weapons: Chaos Energy Whip, Chaos Titan Tails", pp. 48-59
- Fulgrim (Novel) by Graham McNeill
- Mechanicum (Novel) by Dan Abnett
- Age of Darkness (Anthology), "The Iron Within" by Rob Sanders
- Storm Of Iron (Novel) by Graham McNeill
- Titanicus (Novel) by Dan Abnett
- Soul Hunter (Novel) by Aaron Dembski-Bowden