Thousand Sons

"The minds of gods are not for mortals to know, or to judge. Accept that Tzeentch has a place for all of us in his grand scheme, and be happy in the part you have to play."

- Proclamation of Magnus the Red

The Thousand Sons are one of the Traitor Legions of Chaos Space Marines who are sworn solely to the service of Tzeentch, the Chaos God of Change, Intrigue and Sorcery, though they were once the Imperium of Man's XV Legion of Space Marines. The main feature that distinguishes the Thousand Sons from the other Traitor Legions is the sheer number of psyker mutations that have always existed amongst the Space Marines in this Legion. Every current member of the Legion possesses psychic abilities and they prefer to use Chaos Sorcerers and guile in combat, relying on their psychic powers and sorcerous knowledge to earn them victory. As a result of an ancient spell known as the Rubric of Ahriman that was cast soon after the Thousand Sons fell from their homeworld of Prospero during the early days of the Horus Heresy, every Thousand Sons Astartes that lacked psychic powers had his soul fused directly into his Power Armour. The Thousand Sons have become living embodiments of sorcery animated by the power of Chaos and the will of the Lord of Change.

Creation of the XV Legion
Like all of their predecessors among the Legiones Astartes, the XV Space Marine Legion was first forged on Terra by the Emperor of Mankind and its original members were recruited from the Terran population. Their gene-seed was first derived from samples of the psychically-gifted DNA of their genetic father Magnus the Red and then implanted into the first Thousand Sons Astartes in the gene-laboratories of Luna during a brief resurgence of Warp Storms within the boundaries of the Sol System. This brief surge of Warp activity generated psychic convergences all across the globe, resulting in spontaneous outbreaks of psychotic violence. This unusual activity likely did not have any additional mutational effect on the Legion's gene-seed. However, upon learning of these ominous events years later after he was given command of the Legion following his discovery by the Emperor on the world of Prospero, Primarch Magnus considered these portents as boding ill for his Legion.

The initial corps of Thousand Sons Legionaries, the Student-Aspirants, had been chosen from psychically-gifted individuals who had been citizens of the former Achaemenid Empire that had existed on Terra and had been ruled by the Emperor for nearly a standard century. Because they had been under Imperial rule for so long, the Achaemenids had not suffered as greatly as other regions of the planet during the Emperor's Unification Wars to reunite all the various techno-barbarian tribes and nation-states of the Earth under his rule.

The Student-Aspirants of the XV Legion had been chosen from among those Achaemenid families the Emperor himself had determined showed potential and were suitable for the gene-seed implantation process. These young men were taken from the territory of the Achaemenid Empire to the Emperor's secret gene-laboratories beneath the Himalayan Mountains, where he first had begun his experiments in human enhancement and created the Primarchs, to begin the Student-Aspirants' transformation into Space Marines. One of these first Student-Aspirants was Ahzek Ahriman and his twin brother, Ohrmuzd Ahriman. Once it had been raised, the XV Legion was deployed by the Emperor to gain experience through the suppression of the few remaining pockets of techno-barbarian resistance on Terra to Imperial rule. Having proved themselves in this first campaign, the XV Legion was formally named the Thousand Sons by the Emperor and given their own expeditionary fleet so that they might begin to make contributions to the Great Crusade the Emperor had unleashed to reunify all of humanity within the newborn Imperium of Man.

Magnus the Red
The world of Prospero was, as records report, originally a place of pure desolation. It was a desolate, dark planet and was chosen by its original inhabitants because of its sheer distance from Terra. Mutants and psykers lived in reclusion and study on the world, safe from the prejudice and hatred of their fellow humans.

In the end, the only good thing about Prospero was its galactic position as a backwater and the reality that it was an easy world to hide on. It had one major city, Tizca, the City of Light, a gleaming metropolis of white marble, with spires reaching into the sky. Tizca was situated on the most central of the many mountains of the planet and it was nourished by underground hydroponics and techno-psychic collectible arrays that provided sustainable energy. All of its towers were gleaming works of architectural grace defined by soaring obelisks and towering pyramids.

Within Tizca, the mutant psychic outcasts of human society devoted themselves completely to the study of their psychic abilities in order to master their powers. Thus Magnus could freely develop his own full psychic potential far from the sight of other men. Time passed and Magnus went from student to adept and from adept to master. When he reached adulthood, someone whose coming he had long foreseen finally arrived on Prospero: the Emperor of Mankind. As legend tells, the two recognized each other immediately. The Emperor, of course, acknowledged the psychic giant to be one of his long-lost sons and granted Magnus the command of the Thousand Sons Space Marine Legion that had been created from his own genetic profile. Bearing Magnus’ gene-seed, the XV Legion had a strong predisposition towards psychic mutation and a considerable number of Thousand Sons Astartes inherited their Primarch’s potent psychic capabilities.

The Great Crusade
Approximately 5 standard years after the Thousand Sons began the Great Crusade to reclaim and reunify the human-settled galaxy, the Thousand Sons’ began to display powerful psychic abilities, which was a welcome development for its Astartes as they sought to further emulate the Emperor. This development was reluctantly tolerated by the Emperor, who was greatly wary of psychic abilities wielded by anyone other than himself or Malcador the Sigillite, because the Thousand Sons' abilities proved to be a powerful weapon for the Imperium during the Great Crusade. Throughout that long campaign, the Thousand Sons made extensive use of sorcerers, and their Warp-derived powers would leave whole populations in thrall to their will rather than carrying out a planetary conquest through a costly full frontal assault like the other Space Marine Legions. This tactic earned the ire of Leman Russ of the Space Wolves Legion who saw anything less then a frontal assault as dishonourable and cowardly. But soon, the Legion's joy at their psychic gifts turned to revulsion and horror as a wave of ghastly, degenerative mutations began to affect large portions of the battle-brothers of the XV Legion. These mutagenic changes began to be called the "Flesh-Change" by the Legionaries, and were much feared, as the spiral of degenerative mutation ultimately reduced a proud Thousand Sons Astartes into a mindless mutant abomination that would later be recognised by the Imperium as a gibbering Chaos Spawn. The majority of those afflicted by the Flesh-Change were put into stasis by the Legion in the hope that someday in the future a cure would be able to be found to reverse the onset of these crippling mutations. The number of active Astartes within the XV Legion soon began to dwindle to dangerously low levels as a result of the ravages of the Flesh-Change.

Fortunately, for the XV Legion the Emperor's Great Crusade finally arrived at the isolated world of Prospero and the Thousand Sons were reunited with their Primarch Magnus. The flesh-change had become a pandemic at this point, but the entire Legion was transported to the newly discovered world to meet their gene-father. After the initial reunion with one of His lost sons and the celebrations that followed, the Emperor and the vast majority of the Great Crusade's large fleet departed Prospero, leaving the Thousand Sons behind. By then the rampant mutations within the Legion had spontaneously gone out of control after the departure of the Emperor. The Thousand Sons Primarch Magnus intervened to save his genetic children, and through mysterious means was able to save those that had been the least affected by the rampant mutations. In the end, the XV Legion only numbered a thousand battle-brothers that had managed to be saved.

The Council of Nikaea
The Thousand Sons gene-seed had been stabilised and the recruitment of potential Initiates from Prospero began to replenish the Legion's severely depleted ranks. The XV Legion was eventually able to rebuild its numbers (though the Thousand Sons Legion would never become as large as its fellow Legions) and return to the Great Crusade, led by their Primarch Magnus. Using their psychic gifts, the resurgent Thousand Sons Legion brought a number of worlds into Imperial Compliance, bringing them into the Imperial fold. Their primary methods of victory included the use of diplomatic guile and trickery, a modus operandi that was not questioned by the rest of the Imperium. But these methods grew less effective as the XV Legion's Expeditionary Fleet entered more dangerous regions of unknown space where extensive hostile forces were encountered. Many of these new enemies of Mankind employed psychic powers similar to those that the Thousand Sons wielded. The XV Legion used their own potent psychic gifts and sorcerous abilities to bring these enemies of Mankind into Compliance or to exterminate them altogether.

Over the following decades some of the Primarchs voiced their dissent that these so-called "psyker" Astartes were allowed to exist and be a part of the Emperor's righteous Great Crusade. Rumours and condemnations began to spread about the Thousand Sons Legion amongst the other Expeditionary Fleets. The most vocal of these detractors were the Primarchs of the Death Guard, Imperial Fists and Raven Guard Legions. The majority of the Astartes of the XV Legion had been afflicted by the rampant genetic mutation within their ranks. Those that still remained unafflicted had seen their psychic abilities increase dramatically in power level. Soon the Thousands Sons' detractors raised their objections to the Emperor himself, calling for the XV Legion's disbandment and for the Legion to be expunged from the Imperial records like the II and XI Legions.

The Emperor was also displeased by the Thousand Sons' dabblings in manipulating the corrupting powers of the Warp and later forbid the use of sorcery by either Magnus the Red or the members of his Legion after an Imperial Conclave was called on the world of Nikaea to deal with the question of psykers. While fighting in the Great Crusade the Thousand Sons would secretly gather the sacred texts and forbidden research into psychic phenomena of several thousand conquered worlds and compile them into the infamous tome of sorcery known as the Book of Magnus.

However, serious suspicion began to surround Magnus as the hatred towards mutants and psykers spread through the Imperium as the Crusade progressed and the Legions learned how dangerous the use of psychic abilities could be on world after world that had been ravaged by them during the Age of Strife. After much debate in the Imperium over the use of psykers, the Emperor called an Imperial Conclave of all the Primarchs and chief Imperial officials at the remote and volatile planet of Nikaea to deal with the issue once and for all. The highest authorities in the young Imperium were present or were represented, including the Emperor and his Sigillite and Regent Malcador, who officiated over the council. At the forefront of the debate was Magnus, who argued very passionately for his cause and the important contributions that psykers and the use of sorcery could make to the improvement of the Imperium and to speeding up the successful conclusion of the Great Crusade. The main opponents to the use of psykers were the Space Wolves who shared their Primarch Leman Russ' hatred of sorcery as unclean and cowardly and the Death Guard, whose Primarch Mortarion testified in person against the use of psychic powers.

When a consensus emerged among the Council's participants that psykers and their powers represented a potential danger to the people of the Imperium, the Emperor's edicts were that in the interest of unity, no one was to be censured for prior actions involving the use of psychic abilities. Use of psychic abilities by the Imperium's military forces was banned (except the use of Astropaths, Navigators, and very strictly sanctioned and controlled psykers who were authorised to carry out Imperial business, like the Sisters of Silence). All Astartes Legion Librarians were to be disbanded, and their members returned to conventional combat duty.

In effect, Magnus and the Thousand Sons were banned from practicing "sorcery" or using the psychic abilities and knowledge they so coveted.

The Fall of Prospero
When Magnus the Red learned of Horus' betrayal of the Imperium and his decision to give his loyalty to the Ruinous Powers, he used his own psychic abilities to get a message to the Imperial Palace on Terra by directly contacting the Emperor mind-to-mind, though this ruptured the Palace's considerable psychic defenses and killed thousands of people whose minds were unable to handle Magnus' potent psychic call. But the Emperor refused to believe that his favorite son Horus would ever betray his trust and so he assumed that it was Magnus who had been corrupted by the Chaos Gods since he was once again using the sorcerous powers that had been banned by the Council of Nikaea. Believing that Magnus sought to sow dissension in the Imperium to serve his masters in the Warp, the Emperor ordered the Space Wolves Legion to go to Prospero and bring back Magnus to Terra, so he could give account for his actions. But this was not to be, as the corrupted Warmaster Horus had intercepted the Emperor's communique with Russ' Legion and subtly manipulated their orders. Instead of just arresting the offending Primarch Magnus for his transgressions and bringing him back to the Emperor for censure and punishment for breaking his oath never to use his psychic powers again, Horus changed their orders to read that the Space Wolves were to assault the Thousand Sons' homeworld of Prospero. Magnus had psychically foreseen the Loyalist Marines' attack on Prospero, which was eventually carried out by the Space Wolves Legion, elements of the Emperor's Adeptus Custodes, and millions of Imperial Army troops, all assisted by the Sisters of Silence acting as psychic "blanks" in order to nullify the Thousand Sons' psychic abilities.

Magnus had finally understood, after his forced psychic entry into the Hall of the Golden Throne and his direct mental communication with the Emperor, that he had been manipulated by Tzeentch, with whom he had apparently unknowingly consorted with while desperately looking for a way to stop the emergence of the psychic mutations that were threatening to destroy his Legion. In an act of repentance and sacrifice, and to show his father that he and his Legion were loyal to the end, he did not warn the defenders of the planet or his Legion of the coming Imperial attack, on the contrary, he imposed a psychic veil on the planet so the Thousand Sons would have no clue of the impending assault. He also dispersed the Thousand Sons' Legion fleet far away from Prospero. He knew that Tzeentch wanted the Thousand Sons and Space Wolves to slaughter each other, and he wanted to stop these plans, even if it meant the sacrifice of his Legion and homeworld. Therefore, the Space Wolves' attack on the Thousand Sons' homeworld of Prospero came as a complete surprise. Because there was no warning, the invading fleet translated from the Warp into realspace practically on top of the planet, and quickly destroyed its orbital defences, initiating the great campaign of the Horus Heresy known as the Fall of Prospero to Imperial historians.

Then, a tremendous orbital bombardment reduced Prospero to cinders, except its capital, Tizca, a beautiful city and the seat of Magnus and the Legion, that was at all times protected by a psychic void shield. This shield was maintained by one of the Thousand Sons' cults, and Magnus did not disable it, knowing that such action would alert his Legion. Because of the shield, an Imperial invasion of Tizca had to take place. A huge force of landing vehicles and support craft descended on the city, whose defenses had been left mostly unmanned. Establishing a beachhead in the spaceport area, the Space Wolves began slaughtering thousands of Prosperans and burning everything in sight. Yet the Thousand Sons' rank-and-file did not share Magnus' acceptance of defeat and punishment, so they took up arms against the Loyalist invaders. The Thousand Sons managed to hold Tizca (the only surviving city on the planet) for a period of time before they were eventually pushed back. Magnus eventually, reluctantly, took to the battle against the Loyalist forces when Leman Russ and his Wulfen were unleashed on the last standing Pyramid of Tizca. Magnus and Leman Russ took part in a devastating duel in which Russ was ultimately victorious. Magnus invoked ancient sorceries in order to escape Prospero by opening a gateway through the Warp into the Eye of Terror where a Daemon World had been prepared for Magnus and the remnants of his Legion by their new patron, Tzeentch. Magnus was subsequently "rewarded" by Tzeentch by being transformed into a Daemon Prince.

Following the siege of Prospero, the Thousand Sons have been the arch-enemies of the Space Wolves Chapter. They have tried several times to uproot and destroy the Space Wolves, including establishing a Chaos temple in a mountain spire on the Space Wolves' homeworld of Fenris, a temple to Tzeentch known as the Daemonspire whose creation was ordered by Madox, a high-ranking Chaos Space Marine in Magnus' service. The Thousand Sons tried again on the world of Garm by stealing the Space Wolves artefact known as the Spear of Russ to perform a sorcerous ritual that would transform the planet into another Daemon World of the Warp. Even though the Spear was lost, the world was saved from Chaos and retaken for the Emperor by the Imperial Guard. In this instance, Ragnar Blackmane defeated Madox and cast the Spear into a partially manifested Magnus, losing the Spear but banishing Magnus back to the Warp.

Magnus' Vengeance on the Space Wolves
Revenge for the Thousand Sons finally came against the Space Wolves in the 32nd Millennium, even though most of those Loyalist Astartes of that Chapter who had originally fought against them had died and passed on long centuries before. The Thousand Sons began raiding worlds around Fenris, attempting to bait Great Wolf Harek Ironhelm away from his homeworld, because he wanted nothing more than to bring the Thousand Sons to battle. Magnus even taunted him in his dreams, showing Harek the smoldering remains of conquered cities which Magnus was walking through. Eventually Harek found what he believed to be the Thousand Sons’ secret base on Gangava and launched a full scale attack against it. This allowed the Thousand Sons to assault Fenris itself. For forty days and nights, the Thousand Sons assaulted the Fang Citadel, and the defending Space Wolves were forced to awaken Bjorn the Fell Handed, now a Venerable Dreadnought. The remaining Space Wolves troops retreated deep into the Fang, while sending scouts out to escape and inform Harek. Harek returned to Fenris and brought the battle to Magnus. Magnus, now a Daemon Prince, was too powerful for Harek however, and slew him on the slopes of the Fang but not before taking a terrible wound himself. When the Space Wolf Chapter fleet returned, the Thousand Sons withdrew from Fenris back into the Warp, but were pleased at the death of the Space Wolves' Chapter Master.

The Rubric of Ahriman
Some time later, the surviving Thousand Sons Marines began to suffer severely once more from the constant mutations of their genomes that were always a result of time exposed to the Chaos energies of the Eye of Terror. In addition, the Thousand Sons' patron Chaos power Tzeentch was the very embodiment of Change, and he often gave mutational "gifts" to those who served him. Soon after their arrival in the Eye of Terror, several of the Thousand Sons' Battle-Brothers were mutating out of control into mindless Chaos Spawn. All their medical efforts to staunch the spread of mutation were for naught. The Thousand Sons were losing the only thing they had left after the Horus Heresy and the destruction of Prospero, their humanity.

The Chief Librarian of the Thousand Sons and long Magnus' closest friend and adviser within the Legion, a powerful Chaos Sorcerer named Ahzek Ahriman, devised a way to prevent further mutation in the form of a powerful spell known as the Rubric of Ahriman. However, the rest of the Sorcerer Librarians of the Thousand Sons did not agree or see eye-to-eye on the matter. It was only when Magnus was finally elevated to the status of Daemon Prince of Tzeentch that the Sorcerers banded together to create a Cabal. They agreed to cooperate and unleash the Rubric. The following sorcerous cataclysm unleashed lightning strikes that hit each and every Thousand Sons Chaos Marine. Those that had little or no psychic power were disintegrated outright, their bodies turning to ash within their armour. Those that possessed psychic power found those abilities greatly augmented, becoming among the most powerful sorcerers in the galaxy, yet their souls were fused with the very essence of their Power Armour as a result, creating a horrific hybrid of man and machine.

The Cabal of Ahriman
Magnus was about to destroy Ahriman and his Cabal for what they had done to his Legion, but just as he was about to strike, the Cabal was saved by Tzeentch who revealed: "You destroy my pawns too easily." Ahriman's Cabal were instead exiled from the Thousand Sons' Planet of Sorcery for their actions by the Daemon Prince Magnus the Red. Magnus cursed Ahriman to 'wander the galaxy in search of the true meaning of Chaos. Instead, Ahriman now seeks out sacred artefacts and talented psykers to corrupt them to Chaos and add them to the arsenal of the Ruinous Powers; the threat presented to the Imperium by the Cabal of Ahriman is so great that the Inquisition will sooner destroy a precious artefact than allow it to fall into Ahriman's hands. Despite the Inquisition's opposition, Ahriman has successfully wandered the galaxy gathering up promising new cult members and artefacts on thousands of worlds for the last several millennia.

Ahriman's Current Dealings
Ahriman is currently seeking entry into the Eldar's Black Library in a hidden branch of the Webway and during Abaddon's 13th Black Crusade was able to gain access to the Webway using the captured Inquisitor Czevak and a long-forgotten Webway portal on Etiamnum III. It is rumored that if Ahriman secures entry to the Black Library, he could use the information inside to become a new and powerful Chaos God.

After summoning "Leviathan," a giant flying Warp Beast wreathed in flame, a cyclopean daemonic monstrosity with Screamers that follow in its wake, disrupting not only the Warp but the Webway as well, and causing horrendous casualties on both sides of the conflict, Ahriman was ejected from the Webway with his goal unattained. Inquisitor Czevak was captured by the Eldar's Harlequins and is believed to be still held in the Webway. The Webway gate Ahriman used was later sealed by the Eldar, never to be opened again. The final results of the Thirteenth Black Crusade indicated that Ahriman's 'star is on the rise' with Magnus once again, mostly due to the great chaos caused by his battles in the Webway, the prowess he displayed in capturing Inquisitor Czevak, and the ability he displayed to come close to entering the fabled Black Library.

Ahriman himself believes to this day that Chaos can be controlled and used effectively with enough strength of will to master its willful eddies and a powerful mind to focus its demands. While often portrayed as the Hero of Tzeentch, he instead believes he is serving his own goals, despite being just a pawn. He does not openly recognize Tzeentch as his master, though all his machinations by definition empower Tzeentch.

Notable Campaigns

 * Unification Wars, Pacification of the Boetian Lowlands (Unknown Date.M30) - When the XV Legion was created they were used to quell the few pockets of isolated resistance to the Emperor's rule that remained on Terra during the Wars of Unification. Boetia was a nation that had existed since the Age of Strife and was chiefly known for holding out against the Unification for a considerable period of time until it was finally forcibly incorporated in the newborn Imperium. The ruling family, the Yeselti, attempted to stubbornly cling to power, forcing Imperial Army forces to invade their province the Astartes of the XV Legion were sent in to finally crush any further resistance in a brilliant campaign that lasted only six weeks. Shortly after achieving this objective, the XV Legion was formally named the Thousand Sons by the Emperor Himself and was sent out into the galaxy as part of his Great Crusade. This particular conflict holds the distinction of being the final campaign of the Unification Wars that took place during the Great Crusade.
 * Kamenka Troika (Unknown Date.M30) - This was a campaign of extermination waged in the middle years of the Great Crusade against the barbaric Greenskins (Orks) of the Kamenka Troika. The Emperor had issued the writs of war, commanding the Thousand Sons, the Legio Astorum Titan Legion and a Lifehost of PanPac Eugenians of the Imperial Army to drive that savage race of xenos from the three satellite planets of Kamenka Ulizarna, a world claimed by the Adeptus Mechanicus of Mars. The savagery of that war, the slaughter and relentless, grinding attrition had left tens of thousands of dead in its wake. The Imperial forces proved victorious after two standard years of fighting and earned a score of honours for their war banners. Victory had been won, but the cost had been high. The Thousand Sons sustained severe losses of 873 Battle-Brothers of the 5th Fellowship, effectively wiping the 5th out as a functioning unit. This forced Magnus the Red to reduce his Legion from ten Fellowships to the Pesedjet, the nine classic Fellowships of Prosperine antiquity.
 * Aghoru Campaign (Unknown Date.M31) - The Imperial Compliance of the world of Aghoru (officially codified in Imperial records as 28-16) was an action carried out by units of the Thousand Sons Legion that was achieved through diplomacy and was considered a success; secondary combat against apparent Warp denizen infestation (beings known to the local population as "Elohim") within the subterranean passages of a titanic peak that stood taller than Olympic Mons on Mars. The Thousand Sons forces were enhanced by a small unit drawn from the Space Wolves Legion during this operation.
 * Ark Reach Cluster (Unknown Date.M31) - The Ark Reach Cluster had been discovered by the Word Bearers Legion's 47th Expeditionary Fleet; it was a group of binary stars occupied by a number of belligerent planetary empires that rejected the Imperium's offer to become part of the Emperor's growing demesne. This Imperial Compliance action of the Great Crusade was carried out through the combined efforts of the Thousand Sons working in concert with elements from the Space Wolves and the Word Bearers Legions. The first four star systems fell to the Word Bearers and Space Wolves. But the fifth and sixth world, known as Shrike, required the assistance of the Thousand Sons. The return to the XV Legion of the dreaded mutational "flesh-change" occurred at the conclusion of this campaign and helped to bring on the eternal enmity between the Space Wolves and the Thousand Sons whom regarded their cousins as "impure."
 * Fall of Prospero (Unknown Date.M31) - The Fall of Prospero was the name given by later Imperial scholars to the sanctioned Imperial military reprisal against the XV Legion's homeworld of Prospero at the start of the Horus Heresy in the early 31st Millennium. The action was carried out by the Space Wolves Legion and elements of the Legio Custodes and the Sisters of Silence as a punishment for the Thousand Sons' flagrant violation of the Emperor of Mankind's edicts against the use of sorcery made at the Council of Nikaea. Though the Thousand Sons' Primarch Magnus the Red was aware of the impending assault and the vulnerability of orbital attack, he chose not act, as he felt that his sins warranted the Emperor's sanctions against him. The Space Wolves viciously bombarded the surface of planet and then launched a massive orbital strike with devastating results, slaughtering all life on the surface of Prospero. The battle finally concluded with Magnus and Leman Russ facing one another in personal combat, which resulted in the Red Cyclops being cast down and his back broken. Seeing his imminent demise near at hand, Magnus cast a mighty spell that took the great city of Tizca, his remaining Astartes and what precious archives of forbidden lore they could save, to their new homeworld known as the Planet of the Sorcerers, prepared by their patron Chaos God Tzeentch somewhere within the Eye of Terror.
 * First Battle of Garm (Unknown Date.M31) - In the aftermath of the Horus Heresy, the Thousand Sons attacked the Space Wolves' Shrine World of Garm, which was named for a famous Wolf Lord from the earliest days of the Space Wolves Legion who had given his life defending the Primarch Leman Russ from an attack by Magnus the Red. Leman Russ raised a cairn to Garm upon the place of his death and placed the Spear of Russ, the mighty weapon gifted to him by the Emperor Himself which had wounded the Traitor Magnus, atop Garm's tomb. The Space Wolves were able to fight off the Thousand Sons Traitor Legion and drive them from the world.
 * First Battle of The Fang (Unknown Date.M32) - During the 32nd Millennium, Harek Ironhelm had risen to command the mighty Space Wolves Chapter as its Great Wolf. After the end of the Horus Heresy, Magnus the Red was determined to have his revenge for the devastation of his homeworld of Prospero at the hands of his former brother Leman Russ and his Legion. He devised a cunning plan to lure the Space Wolves into a trap in order to enact his final vengeance against them. Despite the grievous damage Russ had inflicted on them, the Thousand Sons still had the potential to launch raids into protected space, and the knowledge of that burned within Ironhelm. It had burned within him for decades, until nothing else seemed important. Despite all the resources he devoted to hunting Magnus, the chase had always come up short. There were always signs left behind for them to find, mocking hints, challenges to catch the originator of the ruin. After many fruitless efforts to catch up with the Thousand Sons, Harek became obsessed, and took to searching worlds along the edge of the Eye of Terror itself. Eventually he found what he believed to be the Thousand Sons' secret base on the world of Gangava and launched a full-scale planetary assault against it. In this he was deceived, for though Gangava was held by a strong garrison of the Forces of Chaos allied to Magnus, they were but a distraction. Even as Harek attacked Gangava, the fleet of the Thousand Sons and their Chaotic levies appeared in orbit over Fenris. The Fang, the Space Wolves' fortress-monastery, was held only by a skeleton force of Space Wolves and their feudal thralls. For forty days and forty nights the Thousand Sons assaulted the mighty citadel. Bjorn the Fell-Handed, the most ancient of the Space Wolves' Dreadnoughts, was awoken from his long slumber and took charge of the Chapter's defences. Under Bjorn's direction, the Space Wolves fell back to the innermost chambers of The Fang, collapsing the tunnels as they went. Simultaneously, a force of Scout Marines, under Haakon Blackwing, managed to escape from the citadel and take ship to Gangava, bringing word of the siege to Harek. Overcome with fury and shame at his folly, the Great Wolf immediately took ship to Fenris, bringing the might of the Space Wolves with him. Finally, on the upper slopes of The Fang itself, the Great Wolf met Magnus in battle on the final day of the siege. Ironhelm's assault against the Sorcerer Primarch was stoked by rage, the rage he had cultivated ever since leaving Gangava. The Daemon Primarch proved to be too powerful and slew Harek, but not before taking a terrible wound himself. Before dying, the Great Wolf took solace knowing that his Wolves had already penetrated The Fang. His Wolves would hunt down every invader in those halls, one by one, driven by the remorseless focus that had always been their badge of honour. The Thousand Sons withdrew before the blood-maddened Space Wolves. It was not known by what means the Traitor Marines escaped vengeance. Many did not and were killed in the tunnels. But others, including most of the Traitor Legion's Chaos Sorcerers, disappeared from Fenris at the same time their fleet achieved the in-system Warp jump-points. The Wolf Priests speculated that Magnus himself departed in the same sorcerous manner, though there were no witnesses to his leaving.
 * Second Battle of Garm (Unknown Date.M41) - During the 41st Millennium, the Thousand Sons Traitor Legion once again assailed the Shrine World of Garm. Led by the foul Thousand Sons Chaos Sorcerer Madox, a Chaos Cult uprising on a planetary scale provided the necessary cover for the sorcerer to steal the sacred Spear of Russ. Soon a great portion of the Space Wolves Chapter was deployed to Garm to help quell these massive uprisings. During a climatic battle between the Chaos Sorcerer and Ragnar Blackmane, the young Space Wolf hurled the sacred Spear of Russ into a Warp portal to prevent the summoned Daemon Prince Magnus the Red from entering realspace and turning the tide of battle. Though even the Space Wolves' Great Wolf Logan Grimnar believed that Ragnar's actions had saved the Chapter from a potential disaster, many Space Wolves believed Ragnar had dishonoured himself and his fellow Battle-Brothers by losing one of the Space Wolves' greatest relics.
 * Arcadia (Unknown Date.M41) - The infamous Chaos Sorcerer Ahriman lead his Chaos Space Marine warband known as the Prodigal Sons to the Eldar Harlequin world of Arcadia to plunder the Arcadian Librarium, one of the most extensive repositories of knowledge in existence. Astartes under the command of Captain Gabriel Angelos of the Blood Ravens Space Marine Chapter, alongside a loose alliance of Harlequins, fought against Ahriman and his minions in order to foil their attempts to gain knowledge from the library. Ahriman was attempting to steal certain texts in order to gain access to the Webway, but the Harlequins deceived Ahriman about where the entrance of the Webway Gate lead, preventing him from achieving his ultimate goal.
 * 13th Black Crusade (999.M41) - The Thousand Sons Traitor Legion fought alongside Abaddon the Despoiler's 13th Black Crusade, and were highly active in the Cadian and Prospero Sectors. Ahriman attempted to lead his Prodigal Sons warband into the Eldar Webway in order to discover and gain access to the forbidden Eldar Black Library. Ahriman was able to gain access to the Eldar Webway using knowledge extracted from the captured Inquisitor Czevak. Czevak had been the only human ever invited by the Eldar to be a "guest" of the hidden Eldar Craftworld that is the Black Library -- in reality he had been used by the Eldar as bait and a foil for Ahriman. Ahriman subsequently entered the Webway through a long forgotten portal that was discovered by his minions on the world of Etiamnum III, a planet bequeathed to the care of the Imperium by the Eldar of Craftworld Altansar before that Craftworld had been lost in the Eye of Terror millennia before. This intrusion was considered a major setback by the Eldar Farseers who had failed to foresee it, and none other than Eldrad Ulthran himself, the greatest of the Eldar Farseers, had to be summoned from Ulthwé to lead the Eldar defence against the breach. Ahriman was eventually repulsed, and the Webway gate he had used to gain entry was sealed, never to be opened again. The secretive Order Psykana, which consists exclusively of Blood Ravens Librarians, was also called to help defeat the Traitors but arrived too late, and they subsequently took over the protection of the Reclusium that housed the portal.

Legion Homeworld
Prospero was chosen by its original settlers for one reason: its remoteness. Isolated from the most common Imperial travel lanes and boasting virtually no independent resources of any value, Prospero had only one redeeming quality: it was a good place to hide. In the end, it was not even that. Today it is a blasted ruin, declared Purgatus by the Inquisition.

Through the millennia of endless raiding since, it has been discerned the City of Light survived its transit through the Immaterium intact. It came to rest within the Eye of Terror, upon a world that has come to be known as the Planet of the Sorcerers. That daemonic place is a seething cauldron of magical power, reflected across its breadth in the form of infernal volcanism and tempestuous skies saturated with magical vapour. Towers jut from craggy fists of rock thrust up from plains of lava, twisted and obscene mockeries of the spires and pyramids of learning which were the hallmarks of the City of Light before its fall. Mightiest of them all is the obsidian monolith that is the Tower of the Cyclops, said to be so massive it can be discerned from space with the naked eye. More obscenely, the Tower of the Cyclops looks back, as the pinnacle of the obelisk is a glowing warp eye, through which Magnus watches the paths of the future. The Silver Towers of the City of Light have been transfigured by the sorcerous might of the Thousand Sons into space-faring fortresses in which psyker lords set out from the Planet of Sorcerers to traverse the cosmos, launching vengeful assaults upon the Imperium of Man.

Legion Organisation
The organisation of the Thousand Sons before the coming of Magnus is not currently known but it is recorded that they were not considered particularly different from the organisation of a typical Astartes Legion apart from their unusually high number of battle-brothers that possessed psychic abilities which resulted in the Legion possessing the most powerful Librarians during that era. When Magnus took over command of the Thousand Sons, he instituted organisational and hierarchical changes within his Legion. Units known as Chapters in some of the other Legions which contained approximately 1000 Astartes were now referred to as "Fellowships" within the Thousand Sons. The most Fellowships the Legion was able to field when they rebuilt the Legion never numbered more than ten.

However, at the conclusion of the particularly bloody Kamenka Troika Campaign where the Thousand Sons had lost nearly nine hundred Astartes, this effectively wiped out an entire Fellowship. Rather than rebuild the decimated Fellowship, Magnus decided to reorganise and maintain the Legion with only nine Fellowships. This organisation was referred to as the Pesedjet. The legion's command structure was adapted in accordance with Prosperine philosophy and were now known as the Rehati (or the coven of Magnus) a secondary command-track in which the Legion's senior officers were ranked according to psychic ability and influence

As part of their training, all Captains of a Fellowship undertook a secondment to another Space Marine Legion to learn its ways and further the Thousand Sons’ understanding of the galaxy and pursuit of knowledge. Khalophis had served with the Iron Warriors, a Legion he admired and ranked second only to the Thousand Sons. Phosis T’kar fought alongside the Luna Wolves, and never tired of regaling his brothers with tales of meeting Horus Lupercal, or boasting of his close friendship with Hastur Sejanus and Ezekyle Abaddon, the First Primarch’s closest lieutenants. Hathor Maat’s secondment had seen him serving with the Emperor's Children in their earliest days as they fought alongside the Luna Wolves. As Hathor Maat told of his experience to his fellow Captains, he had caught the Phoenician’s eye with his perfectly moulded features, and had fought within his sight on many an occasion. Maat’s proudest possession was an Oath of Moment carved by Fulgrim, and fixed to his breastplate as he took his leave to return to Prospero. Uthizzar’s secondment had been amongst the shortest ever served, lasting a little less than a Terran year with the Space Wolves. Ahriman had spent five years with the Word Bearers, learning much of their Legion and methods of war.

Magnus placed great faith in his subordinates, believing he had taught them well, that their powerful sorceries gave them the necessary tools to function independently of him. Before the Heresy, individual Thousand Sons squads were not led by Veteran sergeants but by those who showed the most psychic promise. These "thrall-wizards" were apprenticed to more experienced Sorcerers for their cabalistic training, but at the same time gained experience leading men in small units. While this practice meant it was rare for a Thousand Sons Astartes who did not possess some measure of psychic talent to become a ranking officer, it also meant those Sorcerers who did gain prominence had considerable combat experience. As a result, the Thousand Sons, a numerically small Legion to begin with, rarely took to the field en masse. Instead they campaigned in smaller detachments under the command of Sorcerers who often acted with much more authority independent of their Primarch than the officers of other Legions. This command experience has stood them in good stead as independent leaders of Chaos Space Marine warbands since the Heresy, to the Imperium's considerable and continuing misfortune.

Specialist Units
When Magnus the Red reorganised the hierarchy and organisational structure of the Legion he had three specialist units created -- the Rehati, the elite Scarab Occult Terminators and the Hidden Ones of the Scout Auxillia.
 * Rehati - The Rehati was the XV Legion's inner coven of advisors and was comprised of the most trusted confidants to Magnus the Red throughout the Great Crusade until the start of the Horus Heresy. The Rehati were drawn from the ranks of the elite Captains of the Thousand Sons' Fellowships to address whatever issues were currently concerning the XV Legion. Its members were ever-changing, and inclusion within the Rehati was dependent on many things, not least of which was an Astartes' standing within the Legion. The Cults of the Thousand Sons vied for prominence and a place in the Primarch's inner circle, knowing that to bask in his radiance would only enhance their powers. As the power of the Empyrean waxed and waned, so too did the mystical abilities of the Cults. The Rehati served a similar position for the Thousand Sons that was comparable to the Mournival of the Sons of Horus Legion.
 * Scarab Occult (Sekhmet) - The specialist unit known as the Scarab Occult were also sometimes called the Sekhmet or Magnus' Veterans. They were made up of the best and brightest of the the Thousand Sons Legion and equipped with crimson-coloured Tactical Dreadnought Armour. The Sekhmet were active throughout the Great Crusade and the Horus Heresy. The Scarab Occult were all members of the elite 1st Fellowship, under the command of 1st Fellowship Captain Ahzek Ahriman. These proud and extremely devoted warriors were both combat Veterans and highly-ranked members of the psychic mastery cult system of the Thousand Sons. None of the Sekhmet were below the Cult grade of Philosophus, the final Cult rank a warrior could hold before facing the Dominus Liminus. Each warrior was able to mentally transcend their physical and emotional weaknesses; achieving a form of emotional purity that resulted in warriors who were both fearless and willing to follow orders immediately and unquestioningly. This extraordinary level of discipline was commented on by some of the other Primarchs who witnessed the Sekhmet in action during the Great Crusade. The Great Khan of the White Scars Legion, Jaghatai Khan, commented that they were no better than automata, whilst, in a similar vein, Ferrus Manus of the Iron Hands Legion likened them to robots, though some within the Thousand Sons suspected that knowing the Iron Hands' affinity for technology, this comment may have been meant as a form of compliment. Leman Russ, the Great Wolf of the Space Wolves Legion, showed disdain for what he perceived as the Sekhmet's perceived "lack" of fighting spirit and espirit d'corps due to their taciturn natures. The Sekhmet's status following the Thousand Sons Legion's transformation into a Chaotic Traitor Legion devoted to Tzeentch and the enactment of the Rubric of Ahriman is unknown.
 * Rubric Marines - The Rubric Marines are the remnants of Astartes warriors of the Thousand Sons Legion who were inadvertently created when the Chaos Sorcerer Ahriman cast an incredibly potent spell called the Rubric of Ahriman to halt the process of degeneration and mutation caused by the energy of the Empyrean that afflicted his Battle-Brothers after they had escaped to the Eye of Terror and were exiled to the Planet of the Sorcerers. Though their corruption was halted by the spell and they were now devoid of mutation, they were all but stripped of independent will as well. Rubric Marines are basically living suits of armour which still move and function, and can respond to orders just like a sentient man, though they are little more than automatons. They quickly fall into inactivity unless a Thousand Sons Chaos Sorcerer is nearby to direct them, although in the fire of combat something of their former battle hunger returns and they move with greater clarity and purpose. The Thousand Sons' Chaos Sorcerers use their Rubric Marine brethren as bodyguards and enforcers as well as guardians for the great libraries of grimoires and vaults of ancient scrolls held by the Sorcerers of the XV Legion. The Rubric Marines are particularly excellent in this role, for they have no spark of curiosity left and are utterly loyal to their psychic masters.
 * Hidden Ones (Scout Auxilia) - The Hidden Ones were a specialist unit of the Thousand Sons that served as the Legion's Scout Auxilia. There is very little in the way of information of how this mysterious unit was deployed or what kind of operations it undertook. Imperial historical accounts show that there is the distinct possibility that these specialised reconnaissance troops served a far more sinister role for the XV Legion that was more akin to espionage agents than a unit of typical Scout Marines composed of Astartes Neophytes engaged in reconaissance-in-force and combat infiltration missions, though the Hidden Ones also carried out those types of missions. An operative of the Hidden Ones would infiltrate a target organisation of interest to gather intelligence while operating under a cover so deep that they never even realised that they had been psychically-reprogrammed to act as a sleeper agent for the Thousand Sons. The Hidden One's status following the Thousand Sons Legion's transformation into a Chaotic Traitor Legion devoted to Tzeentch and the enactment of the Rubric of Ahriman is unknown.

Cults of the Thousand Sons
The Thousand Sons, like some of their more independent-minded Astartes Legions, employed a non-standard organisation within the Legion that were known as Cults and into which every Astartes was placed based upon their level of psychic ability. Though some Thousand Sons Astartes never developed any measurable amount of psychic ability after being implanted with the Legion's gene-seed, the majority did develop some form of psychic ability just like their Primarch soon after competing the implantation process. The Legion used these 5 different Cults to develop and improve the abilities of the often powerful psykers found amidst this Legion's ranks. Membership within these Cults was determined regardless of the Fellowship (Chapter) to which each Astartes belonged within the Legion since Cult membership was based upon what type of psychic ability a Thousand Sons Astartes displayed most affinity for. Each Fellowship was usually made up of Astartes coming from all 5 of the Cults within the Legion though it was not unheard of for a Fellowship's membership to be dominated by the members of just one of the Cults.

These 5 Cults had been founded within the Legion by the 9 original members of Magnus the Red’s inner circle or cabal collectively known as the Rehati. The Rehati had each earned mastery in one of the 5 recognised psychic disciplines. Each Cult was formed to further the development of one of the recognised psychic aptitudes; the Athanaeans focused on telepathy, the Corvidae sought to develop their precognitive abilities, the Pavoni learned to make use of physiokinesis, the mental manipulation of one's own physiological processes, the Pyrae plumbed the secrets of fire, a discipline called pyrokinesis, and the Raptora mastered the potent power of telekinesis. The leader of each Cult bore the rank of Magister Templi. The leader of all the Cults was known as the Magus and this was a rank exclusively held by the Legion's Primarch, Magnus the Red. The highest rank within the Cult system was that of Ipissumus, a grade which represented a being free from limitations, who lives in balance with the corporeal and incorporeal universe. For all intents and purposes, the Ipisssumus was the most perfect being in the universe. This esteemed rank was represented by the most powerful human psyker in existence -- the Emperor of Mankind.

In Prospero's capital city of Tizca each Cult maintained its own pyramidal headquarters, which served as both a repository of the arcane knowledge that they had collected about their chosen psychic disciplines from across the galaxy as well as training facilities specifically geared towards enhancing psykers who displayed strength in one of the 5 recognised psychic disciplines. Each of these pyramids' front gates was topped by the great golden icon that represented the Cult, save for the pyramid of the Pyrae, whose pyramid was topped by an ever-burning flame and whose gate was guarded by Canis Vertex, a Warlord-class Battle Titan of the Legio Astorum that would see action during the Burning of Prospero.

To further represent the distinctiveness of the Cults' members, the Astartes from each Cult would display the Cult's insignia upon the shoulder plates of their Power Armour, with the Cult's distinctive icon placed within the center of the Legion's Pre-Heresy Chapter badge as displayed above.

The five Cults of the Thousand Sons Legion were as follows:
 * Athanaean - The Athanaean Cult's members were practiced masters of the discipline of telepathy, and were able to transmit their thoughts and read the thoughts of others. They often acted as the Legion's communications officers since their communications were secure from all but other psykers and they assisted the Corvidae in conducting intelligence operations based on psychically-gleaned knowledge. While the Corvidae could provide an overall strategic direction based on their reading of the likely probabilities of future events occurring, the Athanaeans could use their ability to read the minds of the enemy to shape the Legion's battlefield tactics more directly, through weapon choice, the types of troops to be deployed and where, and the choice of the most advantageous terrain.
 * Corvidae - The Corvidae were skilled in the psychic discipline of precognition, determining the likely probabilities of future events. They served as the Legion's seers, warning their Battle-Brothers of dangers before they materialised. The Corvidae Cult also helped guide the Thousand Sons Legion along the lines of Fate during times of conflict and in pursuit of their overall psychic and material growth as a Legion. The Corvidae were responsible for much of the Legion's strategic planning. Corvidae could determine events that were not only far in the future but were immediately about to happen, which allowed them, for example, to navigate a minefield before it exploded or to know the exact sequence in which a series of enemy soldiers would fire at a particular target. The Cult badge of the Corvidae was a black raven's head.
 * Pavoni - The Pavoni Cult tended to be the most egocentric of the known Cults within the Thousand Sons Legion, as they had developed the psychic discipline known as physiokinesis. Physiokinesis allowed the Pavoni to manipulate body chemistry and physiology within themselves as well as others, a very useful trait for a group of already superhuman warriors. Skilled practitioners of physiokinesis were able to alter their physical appearance by manipulating the physical characteristics of facial features at will as well as making themselves immune to the harmful effects of dehydration and other physical ailments. On the field of battle, the Pavoni were able to generate lightning by unleashing the inherent bioelectricity of their own nervous systems and focus it offensively, as well as cause the hearts of enemy warriors to explode by literally boiling the blood within their veins. When using these abilities against their foes, the Pavoni had a reputation for venality and spite which boarded on the sickening. The Pavoni were also the designated healers of the Legion, as they were capable of accelerating cellular growth and protein synthesis, which made them extraordinary medics, saving the lives of countless Astartes whom even the Apothecaries could not have saved.
 * Pyrae - The Pyrae were pyrokinetics, meaning that they had developed the ability to both generate and control fire, the power for which was drawn from the Warp. The Pyrae could both generate lethal bursts of fire from their bodies that they could shape into a number of different forms, including projectiles fired from their hands as well as fire shields that could hold back foes and melt away incoming weapons fire. The Pyrae could manipulate existing or standing sources of fire and with their connection to the Warp could lower the temperature of flames striking their own bodies or the bodies of others, effectively making them immune to the effects of fire or great heat. The Pyrae also developed secondary psychic abilities that allowed them to control and manipulate mechanical automata like the robots of the Legio Cybernetica and even the massive Titans of the Collegia Titanica. These secondary abilities were known as technopathy. The Cult badge of the Pyrae was a phoenix wreathed in flames.
 * Raptora - The members of the Raptora Cult were gifted practitioners of the psychic discipline called telekinesis, and were known as telekines. In battle, a Raptora Cult member could psychically fling physical objects at their enemies or rip their enemies bodies' apart through the application of immense telekinetic power drawn from the Immaterium. When used defensively, telekines could generate barriers of invisible kinetic force known as "Kine-Shields" to block physical attacks on themselves or others. During the Burning of Prospero, the massed members of the Raptora Cult generated a massive kine shield over the whole of the city of Tizca intended to protect it from an orbital assault by the Space Wolves. The shield eventually failed when the sheer power unleashed by the Loyalists' assault upon the kine-shield proved to be more than the individual Raptora Astartes could mentally bear. They fell exhausted to the terrible mental strain, one by one, until the psionic shield collapsed.

It is currently unknown what happened to the Cults of the Thousand Sons Legion in the aftermath of the Horus Heresy and their fall to becoming a Chaos Traitor Legion of Tzeentch, as well as the vast changes wrought in the Legion by the Rubric of Ahriman, though it can be assumed that the same range of basic psychic powers not only still exists among the Thousand Sons but has probably been greatly enhanced by their residence within the Eye of Terror and their innate connection to the Lord of Change.

Legion Recruitment
The XV Legion were initially created from Terran stock. After his genetic-sons of the XV Legion were reunited with their Primarch, Magnus the Red's pact with Tzeentch was sealed; only a thousand battle-brother were spared from further corruption of the flesh-change. Throughout the rest of the Great Crusade the Legion recruited exclusively from Prospero, despite the isolated world only possessing a smaller population. Though recruits were only culled in small numbers, many of them were psychically gifted. This resulted in the Thousand Sons being a smaller Legion amongst their fellow Astartes.

Currently it is unknown how the Legion is able to maintain their current strength, although it has been observed only once, that they carried out what appeared to be some sort of resurrection ritual. This magical conjuration allowed their sorcerers to summon the spirits of deceased Thousand Sons from the warp so they could possess a mortal body. They were able to use either a living body or a deceased shell which made no particular difference, as both were effective. These newly possessed bodies then transformed into reborn Thousand Sons battle-brothers.

Legion Combat Doctrine
The Thousand Sons were known to dislike close combat, instead relying on strategy and their psychic abilities. Deceit and guile were their hallmarks, and the legion was commonly criticized for its ways, particularly by Leman Russ, who thought that any battle won by means other than strength and courage was dishonourable. Magnus was confident that he had taught his officers well enough for them to act independently and indeed the legion could function very efficiently without the presence of their Primarch. Following the casting of the Rubric of Ahriman, the Thousand Sons' tactics have changed somewhat to compensate for the effects of the spell, and as a result they now make extensive use of Sorcerers and Aspiring Sorcerers leading squads of slow yet unrelenting Rubric Marines into battle.

Legion Beliefs
For the Primarch Magnus, knowledge was power. He believed there was no discipline his intellect could not master, no secret he could not unlock and make serve his purpose. For the Thousand Sons, knowledge was salvation, the means to controlling the psychic legacy of their Primarch's gene. Every book was sacred, every writing worthy of study, every document a resource to be drained. The ultimate knowledge was sorcery, the way to final enlightenment, the key to the universe. Before the Heresy, the Thousand Sons were publicly dogmatic, swearing oaths of loyalty and singing the Imperial hymns. They fought for the expansion of the Emperor's realm with diligence, but as their oath-breaking illustrated, their final loyalty rested not with the Emperor, but with their Primarch. When Magnus's reach for intellectual mastery exceeded his grasp, Tzeentch was waiting for him, and the Space Marines who believed as he did could do nothing but fall with him.

Legion Gene-Seed
Magnus was unquestionably the most profoundly mutated of the Emperor's Primarchs, both physically and psychically, and the Legion imprinted with his gene-seed reflected that with a high percentage of Thousand Sons manifesting some level of psychic ability. Early in the Legion's history a small, but significant percentage were prone to physical mutation, but in the wake of falling thrall to Tzeentch that percentage escalated wildly. The Rubric ended that forever for the battle brothers of the Thousand Sons, but the sorcerers who command those armoured shells still carry the gene-seed of their Daemon Prince, and wear their grotesque mutations proudly as tokens of their mercurial patron's favour.

Notable Legion Members

 * Magnus the Red - Magnus the Red is the Primarch of the Thousand Sons Traitor Legion and is currently an extremely powerful Daemon Prince of the Chaos God Tzeentch. He was also known during the early years of the Imperium as the Crimson King and the Red Cyclops. A giant in both physical and mental terms whilst still an inhabitant of the Materium, the copper-skinned Magnus possessed tremendous innate psychic ability, and constantly sought to understand the nature of the Warp, becoming a Sorcerer of formidable power. Magnus thought he would be able to control the Great Ocean of psychic energy that was the Warp; however, his prodigious and careless application of his psychic gifts eventually caused him to fall out of favour with his father, the Emperor of Mankind, as well as with the majority of his brother Primarchs. His psychic immaturity, recklessness, and arrogance also caused his own undoing, as it eventually brought about his own damnation and servitude to the Dark God of Change Tzeentch. In the end, Magnus lead his XV Legion to the banner of Horus and fought on the Arch-Heretic's side during the Great Betrayal of the Horus Heresy. He survived those events and ascended to the position of a Daemon Prince of Tzeentch as a reward for his service to the Lord of Change.
 * Ahzek Ahriman - Ahriman is the former Chief Librarian of the Thousand Sons, Captain of its 1st Fellowship and the Magister Templi of its Corvidae Cult. He was banished from the Legion after casting the Rubric of Ahriman using the knowledge of the Book of Magnus, which halted his Legion's corrupting mutations which plagued it after their fall to Chaos, but resulted in the creation of the Rubric Marines. During his banishment, Ahriman has continuously sought out knowledge across the galaxy to bring him closer to an understanding of Tzeentch and Chaos itself and led a warband of similarly exiled Chaos Sorcerers and Chaos Space Marines known as the Prodigal Sons. His actions have recently healed the breach between him and Magnus the Red that was opened by his casting of the Rubric of Ahriman.
 * Phosis T'Kar - Captain of the 2nd Fellowship during the latter days of the Great Crusade and the beginning of the Horus Heresy in the late 30th and early 31st Millennia. As one of the most powerful telekines of the XV Legion, he served as the Magister Templi of its Raptora Cult. Phosis T'Kar met his ultimate fate during the Burning of Prospero, when the Space Wolves Legion, accompanied by elements of the Legio Custodes and Sisters of Silence, were sanctioned by the Emperor of Mankind to punish the Thousand Sons Primarch Magnus the Red for his blatant violations of His Decree Absolute rendered during the Council of Nikaea forbidding the use of psychic powers and the pursuit of sorcery. During the height of the battle, Phosis T'Kar was physically corrupted by the "flesh-change" and surrendered to death at the hands of the Legio Custodes commander Constantin Valdor.
 * Hathor Maat - Hathar Maat was the Captain of the 3rd Fellowship during the latter days of the Great Crusade and the beginning of the Horus Heresy in the late 30th and early 31st Millennia. He also served as the XV Legion's Magister Templi of its Pavoni Cult. Hathar Maat was present during the Burning of Prospero, when the Space Wolves Legion, accompanied by elements of the Legio Custodes and Sisters of Silence, were sanctioned by the Emperor of Mankind to punish the Thousand Sons Primarch Magnus the Red for his blatant violations of the Imperial Decree Absolute rendered during the Council of Nikaea forbidding the use of psychic powers and the pursuit of sorcery. He was one of the few survivors of the massacre who escaped when their mortally wounded Primarch Magnus the Red teleported them to the Planet of the Sorcerers within the Eye of Terror. He would later join Ahzek Ahriman's secret cabal and take part in casting the Rubric of Ahriman in order to stop the "flesh-change" that ravaged the remainder of their legion. Following the casting of the Rubric, Ahriman and his cabal were banished by their angry Primarch. His current whereabouts are unknown.
 * Menes Kalliston - Captain of the 4th fellowship and an Athanaen Cult member. Six months after the sanctioned Scouring of Prospero, Captain Kalliston lead a squad of Thousand Sons Battle-Brothers to the ravaged surface of their homeworld to seek for any signs of survivors or their Primarch. Instead, the squad of Thousand Sons was taken by surprise when they encountered a much larger force of Traitor World Eaters who were also on Prospero for their own nefarious reasons. In the ensuing conflagration, the majority of the squad was killed, and Kalliston was captured by none other than the infamous Captain Khârn of the World Eaters' 8th Assault Company who was the Equerry to Primarch Angron of the World Eaters. Kalliston was subsequently tortured and later killed in a confrontation with Khârn. Only Revuel Arvida, a Sergeant of the 4th Fellowship and a member of the Corvidae Cult, managed to survive.
 * Baleq Uthizzar - Uthizzar was the Captain of the 5th Fellowship during the latter days of the Great Crusade and the beginning of the Horus Heresy in the late 30th and early 31st Millennia following the death of Apophis during the bloody Kamenka Troika Campaign against the Orks. He also served as the XV Legion's Magister Templi of its Athanaean Cult. Following the Council of Nikaea where the Emperor proclaimed a Decree Absolute against the use of psychic powers and the continued forbidden study of the arcane, Magnus continued to dabble with forbidden knowledge despite his father's decree. Magnus continued to dabble in the arcane despite his father's decree. When the Primarch failed to save Warmaster Horus's soul from being corrupted by the Ruinous Powers, he utilised his own psychic abilities to get a message to the Imperial Palace on Terra by directly contacting the Emperor mind-to-mind, though this ruptured the Palace's considerable psychic defenses and killed thousands of people whose minds were unable to handle Magnus' potent psychic call. But the Emperor refused to believe that his favorite son Horus would ever betray his trust and so he assumed that it was Magnus who had been corrupted by the Chaos Gods since he was once again using the sorcerous powers that had been banned by the Council of Nikaea. Believing that Magnus sought to sow dissension in the Imperium to serve his masters in the Warp, the Emperor ordered the Space Wolves Legion to go to Prospero and bring back Magnus to Terra. When Uthizzar accidentally discovered the inevitable attack by the Space Wolves by inadvertently reading his Primarch's thoughts, he was shocked that his gene-sire would withhold such information from his sons. Remorseful at his actions and resigned to his fate, Magnus could not allow Uthizaar to reveal the truth, and so killed him with his powerful psychic abilities.
 * Apophis - Captain of the 5th Fellowship and Ahriman's oldest friend. Apophis, along with the 5th Fellowship, were wiped out during the bloody Kamenka Troika Campaign against the Orks.
 * Khalophis - Khalophis was the Captain of the 6th Fellowship during the latter days of the Great Crusade and the beginning of the Horus Heresy in the late 30th and early 31st Millennia. He also served as the Magister Templi of the Pyrae Cult. Khalophis was present during the Burning of Prospero, when the Space Wolves Legion, accompanied by elements of the Legio Custodes and Sisters of Silence, were sanctioned by the Emperor of Mankind to punish the Thousand Sons Primarch Magnus the Red for his blatant violations of the Imperial Decree Absolute rendered during the Council of Nikaea forbidding the use of psychic powers and the pursuit of sorcery. During the defence of his homeworld, Khalophis sent his consciousness into the inert Battle Titan Canis Vertex, that stood sentinel before the Pyramid of the Pyrae Cult. Initially, the now-living Titan seemed to turn the tide of the battle, but ultimately, Khalophis' victory was short-lived as he was caught in the tremendous explosion of pent-up aetheric energy released by the dying Phael Toron. Khalophis fought to sever his connection to the doomed war engine, but the aetheric feedback lashed back upon him, the fire consuming him utterly, and the entire pyramid of the Pyrae exploded in a searing fireball of glass and steal.
 * Phael Toron - Toron was the Captain of the 7th Fellowship during the latter days of the Great Crusade and the beginning of the Horus Heresy in the late 30th and early 31st Millennia. He also served as the Magister Templi of the Raptora Cult. Toron was present during the Burning of Prospero, when the Space Wolves Legion, accompanied by elements of the Legio Custodes and Sisters of Silence, were sanctioned by the Emperor of Mankind to punish the Thousand Sons Primarch Magnus the Red for his blatant violations of the Imperial Decree Absolute rendered during the Council of Nikaea forbidding the use of psychic powers and the pursuit of sorcery. During the defence of his homeworld, Toron, like many of his fellow battle-brothers, lost control of his Tutelary Dtoaa, who became his devourer and filled him with more power than the greatest master of the aether could contain. Unable to control the pent-up aetheric energy within his body, Toron died spectacularly when his body exploded with the violence of a newborn star.
 * Auramagma - Captain of the 8th Fellowship and a member of the Pyrae Cult. During the Scouring of Prospero, Captain Auramagma attempted to halt the Primarch Leman Russ' destructive rampage, and targeted the Lord of the Space Wolves directly with the full might of his sorcerous powers. Alas for him, Russ' indomitable will and the protections of the Rune Priests proved too strong, and while Auramagma managed to forcibly halt the Primarch, the backblast of his psychic assault incinerated him on the spot.
 * Amon - Amon served as Magnus' tutor before the arrival of the XV Legion on Prospero, and he became one of the Legion's first Prosperine Astartes at the direct invitation of Magnus. Amon eventually rose through the ranks to become Captain of the 9th Fellowship. He became the founder of the Corvidae Cult and its first Magister Templi. He also served as Equerry to Magnus, responsible for the Primarch's security and for officiating certain sorcerous rituals, amongst other duties. Amon would not only survive the battles of the Great Crusade, but those of the Horus Heresy as well, eventually becoming a member of the Cabal of Ahriman and vanishing from recorded history after Ahriman's exile from the XV Legion.
 * Phanek - Founder of the Athanaean Cult.
 * Thothmes - Co-founder of the Athanean Cult along with Phanek. It is unclear whether one or both of the founders were considered the cult's Magister Templi.
 * Ahtep - Founder of the Raptora Cult.
 * Luxan-htep - Co-founder of the Rapora Cult along with Ahtep. It is unclear whether one or both of the founders were considered the cult's Magister Templi.
 * Cythega - One of the 2 founders of the Pyrae Cult. It is unclear whether one or both of the founders were considered Magister Templi of the Pyrae.
 * Memphia - Co-founder of the Pyrae Cult.
 * Imhoden - Co-founder of the Pavoni Cult along with Hastar. It is unclear whether one or both of the founders were considered the cult's Magister Templi.
 * Ankhu Anen - Guardian of the Great Library of Prospero and member of the Corvidae Cult.
 * Mhotep - Mhotep was the Fleet Captain of the Thousand Sons' Strike Cruiser Waning Moon during the Great Crusade; he was killed in action while attempting to destroy the traitorous Word Bearers Legion's massive Battleship Furious Abyss before it could take part in the Battle of Calth. This occurred before the fall of the Thousand Sons to Tzeentch.
 * Sobek - Practicus to Ahriman and Corvidae Cult member.
 * Hastar - Hastar was an Astartes of the 1st Fellowship; Hastar is particularly notable for being the first member of the Legion to fall victim to the flesh-change after the coming of Magnus. He was eventually euthanised by Leman Russ. This is one of the first ever recorded acts of violence of an Astartes killing another and the first known time a member of the Thousand Sons Legion was killed by a member of the Space Wolves Legion. The founder of the Pavoni Cult was also named Hastar but it remains unclear whether or not these Astartes are one and the same.
 * Revuel Arvida - Revuel Arvida was a 4th Fellowship Sergeant and a member of the Corvidae Cult. Six months after the sanctioned Scouring of Prospero, Captain Menes Kalliston of the 4th Fellowship led a squad of Battle-Brothers to the ravaged surface of their homeworld to seek for any signs of survivors or their Primarch. Instead, this squad was taken by surprise when they encountered a much larger force of Traitor World Eaters who were also on Prospero for their own nefarious reasons. In the ensuing conflagration, the majority of the squad were killed and their captain was captured. Like all members of the Corvidae Cult, Arvida was skilled in the psychic discipline of precognition and the determination of the likely probabilities of future events. Despite his bleak circumstances as a captive of the World Eaters, Arvida knew -- as only a Corvidae could be certain -- that death would not find him on Prospero. That was no consolation for all that had been lost, but at least it lent the task of planning his next move a certain urgency. He would survive and live to discover the true causes of his Legion’s destruction, and live to fight them. He would neither pause nor stumble until everything had been revealed to him, everything that would give him a weapon to employ. He is quoted as saying "knowledge is power," suggesting another connection between the Thousand Sons and the Blood Ravens Space Marines Chapter. Ironically, the symbol of the Corvidae Cult is that of a black raven's head. Sergeant Arvida's ultimate fate remains currently unknown.
 * Atharva - Atharva was a member of the Athanaen Cult. As one of the XV Legion's Adept Exemptus, he had attained supreme summits of mastery, aetheric flight, connection with a Tutelary, and the rites of evocation and invocation. He had the distinct honour of serving as part of an Astartes Honour Guard known as the Crusader Host based on Terra in the days just before the start of the Horus Heresy in the early 31st Millennium. The Crusader Host was comprised of members drawn from all 18 of the Space Marine Legions. When news of the Warmaster Horus' betrayal during the Istvaan III Atrocity reached the ears of the Emperor of Mankind, the loyalty of all members of those Legions that had sided with Horus was considered suspect by the warriors of the Legio Custodes. The Custodes imprisoned these Astartes within Khangba Marwu, a vast, underground Imperial prison complex deep beneath the Himalazian (Himalayan) Mountains also known as "The Vault." Atharva was instrumental in affecting an escape, along with several other Astartes of the Crusader Host who became known as the Outcast Dead. Atharva was eventually confronted and executed by the Primarch Rogal Dorn in the Petitioner's City outside the Imperial Palace.
 * Atum Sum - A Chaos Sorcerer of prodigious ability, Atum Sum is known to the Inquisition as an acolyte of Ahriman, Chief Librarian of the Thousand Sons Traitor Legion. He is steeped in the power of the Warp, and a known master of the daemonic. It is said that the daemonic servants of Tzeentch attend him as lesser men command the loyalty of stooping servants, though the veracity of this claim seems unlikely to those versed in the ways of the God of Change. Furthermore, he appeared to have an uncanny mastery of the ebb and flow of possibility, manipulating the shifting tides of the Warp to appear at any time and place he desires. It is doubtless true that Atum Sum is a dire threat to the Imperium, for his appearance is often seen to precipitate daemonic incursions of the most destructive kind. Needless to say, Atum Sum's appearance in the Jericho Reach is a cause for dread, and several groups within the Inquisition have already set in motion plans to discern his purpose and if possible, oppose it. To date, Atum Sum has been encountered in the warzones surrounding the Hadex Anomaly, leading some to suspect that he is involved in some grand scheme to utilise the weird Warp energies streaming from it. Some have even claimed that Atum Sum has conversed with the Anomaly, or with some vast, unknowable intelligence deep inside and beyond it. Whatever the truth, several Inquisitor Lords of the Ordo Chronos were known to be mustering a coalition to stymie his plans when they disappeared, suggesting that his powers are an order of magnitude greater than any had dared believe.
 * Karlsen - After his Legion's fall to Chaos following the Scouring of Prospero, Karlsen became a formidable Chaos Sorcerer and Chaos Champion of Tzeentch. A veteran of the Long War, Karlsen has fought with the Thousand Sons throughout many of its significant moments in history, including the razing of his homeworld by the Space Wolves Legion, the Battle of Terra and countless other campaigns over the last ten millennia. His lifespan has been unnaturally extended by the dark blessings of his patron Chaos God. Over the long millennia, Karlsen has gone completely insane on multiple occasions due to the burden of his cursed, unending existence, though he has been able to perform the blasphemous ritual known as the Dark Communion in order to safely store his memories. As a follower of Tzeentch, he has been "blessed" with noticeable mutations, which include one of his hands fusing with his archaic Bolter, which he is able to operate with his mind. Another mutation he possesses are the unnaturally lengthened, tentacle-like fingers on his opposite hand.
 * Madox - Madox was a notable Chaos Sorcerer of the Thousand Sons who led several plots to destroy his Legion's ancient foes, the Space Wolves Chapter. He reserved a special hatred for the Wolf Lord Ragnar Blackmane, who foiled several plots when they confronted one another across several decades of the late 41st Millennium. It is presumed that he was finally killed on the world of Charys, where Madox hoped to enact a Chaotic ritual to fully corrupt the gene-seed of the Space Wolves and set them on the path of damnation. The ritual used to enact the Chaos Sorcerer's blasphemous ritual was interrupted by the timely intervention of Ragnar Blackmane and his fellow Space Wolves. During their final confrontation, Blackmane managed to wrest the Spear of Russ from Madox and used that sacred artefact of his Chapter to impale Madox through the faceplate of his armour, apparently killing him. Many decades later, while suppressing a Chaos rebellion on an unnamed world, Ragnar Blackmane heard rumours that the sorcerer Madox was still alive and leading the Forces of Chaos. Though unsure if the rumours were true, it could be likely that Madox had indeed been resurrected through malefic means, as he has done so in the past by using the body of a Chaos Cultist. If this is indeed true, then Madox may truly never die, and eventually he could once again return to the material realm.
 * Mordeghai - High Magister Mordeghai, a gifted Chaos Sorcerer, was a Tribune Senioris to Magnus the Red at the Siege of the Imperial Palace during the Battle of Terra. Sometime during the 41st Millennium, Mordeghai had foreseen that if his Death Guard arch-rival Festardius gained control of the world of Mekenna VII, the Plague Lord would use his new influence to turn Mortarion's legions against Mordeghai's cabal. The best way to prevent this from happening was to wrest control from Festardius once the Warmaster Davroth had departed. Mordeghai believed he had more than enough Thousand Sons Rubric Marines at his disposal to accomplish this.
 * Mordant Hex - Hex is one of the Sorcerer Chaos Lords of the Thousand Sons.
 * Tolbek - Tolbek was an Adept of the Pyrae Cult in the sorcerous traditions of Prospero. After his Legion's fall to Chaos following the Scouring of Prospero, Tolbek became a formidable Chaos Sorcerer and Chaos Champion of Tzeentch. Due to the warping influence of the Eye of Terror, the Thousand Sons Legion soon fell to inevitable corruption and mutation. Tolbek was one of the first of the Legion to join Ahriman's secret cabal, intended to find a way to stop the Thousand Sons' genetic degeneration. Tolbek played his part in the casting of the Rubric of Ahriman that destroyed much of the XV Legion and led to the creation of the Rubric Marines, and also shared in the banishment and exile of Ahriman and his followers from the Planet of the Sorcerers on the orders of Magnus the Red. Since that time Ahriman's former cabal, known as the Brotherhood of Dust, had been seeking out the whereabouts of their former mentor, who had gone missing. At some unknown point, the Brotherhood of Dust tracked down the psychic spoor of Ahriman to a warband of Chaos Space Marines known as The Harrowing. Tolbek, escorted by a pair of Rubric Marines, went over to the warband's vessel, the Blood Crescent, to entreat with the warband's leader. During the subsequent audience aboard The Harrowing's ship, Tolbek devised the true identity of Ahriman, who had been masquerading as a lowly sorcerous initiate named Horkos. Recognising Tolbek, and realising his identity had been comprimised, Ahriman unleashed his suppressed sorcerous abilities against both his allies and the Thousand Sons Sorcerer. After killing the majority of The Harrowing warband's leaders, Ahriman was confronted by Tolbek. Ahriman telepathically invaded Tolbek's mind, attempting to devise why he had been sought out. But the cunning Sorcerer immolated his own mind, attempting to destroy Ahriman's mind as well, and Ahriman barely managed to escape Tolbek's insidious trap. Tolbek died as his body erupted into flames, quickly being rendered down into a pile of ash.

Non-Astartes Personnel

 * Mahavastu Kallimakus - Mahavastu Kallimakus hailed from Prospero, from the subcontinent of Indoi, and was a meticulous recorder of data and a fastidious observer of details. He had scribed much of the events of the earliest days of the Great Crusade and had been one of the first Remembrancers to be chosen by the Thousand Sons. His reputation had preceded him, and he was immediately assigned to Magnus the Red. He was at Magnus' side from the time the restored XV Legion had departed Prospero to take part in the Great Crusade. Kallimakus served as Scrivener Extraordinary and the personal scribe of Magnus. He was responsible for transcribing the Primarch's own words into a massive tome known as the Book of Magnus. This tome is one of the most complete treatises on psykers, witchcraft and sorcery in the galaxy, a compilation of all the knowledge and experiments gathered by Magnus during the conquests the Thousand Sons made for the Imperium on the Great Crusade. When the Horus Heresy began, Kallimakus realised his records were a collection of mystic rites now forbidden by the edicts of the Council of Nikaea. Fearing for his safety, he fled with his works before the arrival of the Space Wolves Legion during the Burning of Prospero. His fate after these events are unknown.

Legion Fleet
During the Great Crusade and Horus Heresy eras the Thousand Sons are known to have possessed the following vessels as part of their Legion fleet:
 * Photep (Gloriana-class Battleship) - The Photep served as both the Primarch Magnus the Red's and the XV Legion's flagship during the Great Crusade and Horus Heresy era.
 * Ankhtowe (Battle Barge)
 * Kymmeru (Battle Barge)
 * Scion of Prospero (Battle Barge)
 * Sekhemra (Battle Barge)
 * Geometric (Destroyer) - Commanded by Brother-Captain Menes Kalliston
 * Herumon (Flagship, Unknown Class)
 * Phosis T'Kar (Planet Scourer, Unique Class)
 * Silver Towers of Tzeentch (Capital Ship, Unknown Class)
 * Waning Moon (Strike Cruiser) - Commanded by Fleet Captain Mhotep

Legion Colours
The Thousand Sons' pre-Heresy Power Armour color scheme was red, in recognition of their Primarch Magnus the Red. The Thousand Sons' colors later became Royal Blue with Gold trim after they were converted to the service of Tzeentch and many Thousand Sons Marines began wearing ornate crests on their helmets similar to the striped cloth crowns of the Egyptian pharaohs. Perhaps this is a symbol of those affected by the Rubric.

Legion Badge
The Thousand Sons Legion's badge before the onset of the Horus Heresy was a red "M", which stood for Magnus. The "M" is also the ancient Romanii numeral that stands for the number one thousand, which is the source of the Legion's name. This also reflected the number of Magnus' gene-sons who survived the horrible "Flesh Change" when they finally reunited with their Primarch on the world of Prospero. Others were eventually recruited during the course of the Great Crusade, swelling the ranks of the Thousands Sons. Space Marine Legions were usually comprised at a minimum of ten thousand active Astartes and the Thousand Sons were no different at the height of the Imperium's expansion before the Horus Heresy. Just before the Heresy began, the badge of the XV Legion was altered into a flaming circle, which became the precursor to the Traitor Legion's post-Heresy badge which is the Ouroboros, an ancient symbol depicting a serpent or dragon eating its own tail. The Ouroboros often represents self-reflexivity or cyclicality, especially in the sense of something constantly re-creating itself, the eternal return, and other things perceived as cycles that begin anew as soon as they end.

Gallery
[[Category:T]]