Thousand Sons

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. The main feature that distinguishes the Thousand Sons from the other Traitor Legions is the sheer number of psyker mutations that have always existed among 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.

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, save 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 gleamin 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 dpiral of degenrative 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 now been stabilised and the recruitment of potential initiates from Prospero had begun to replenish their severely depleted ranks. They were eventually able to rebuild their numbers (though the Thousand Sons Legion would never become as large as their 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 compliance, bringing them into the Imperial fold; their primary methods of victory obtained through their standard modus operandi of diplomatic guile and trickery, which was not questioned by the majority of the main body of the Imperium. But soon, however, these methods grew less effective as the expedition fleet entered more dangerous regions of unknown space where more and more 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 psychic gifts and sorcerous abilities to bring these enemies of man into compliance.

Over the following decades some of the Primarchs voiced their dissent that these so-called 'psykers' be 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 Expedition Fleets. The most vocal of these detractors were the Primarch of the Death Guard, Imperial Fists and Raven Guard Legions. The majority of the legionnaires of the XV Legion had been afflicted by the rampant mutantcy within their ranks. But those that still remained unafflicted had their psychic abilities increase to power levels. Soon the Thousands Sons detractors raised their objections to the Emperor himself, calling for the XV Legion's disbandment and have them expunged from the Imperial records like their former Astartes allies of 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 thus banned from practicing "sorcery" or using the psychic abilities and knowledge they so coveted.

The Burning 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 consorted with while desperately looking 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 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 defenses.

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 survivng 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 th 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's13th 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. Inquistor 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 Inquistor 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 (Circa Late 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. 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.
 * Great Crusade, Kamenka Troika (Circa 100.M31) - 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, a Titan Legion from the Legio Astorum and a Lifehost of PanPac Eugenians (Imperial Army) to drive that savage race of xenos from the three satellite planets of Kamenka Ulizarna, a world claimed by the Mechanicum of Mars. The savagery of that war, the slaughter and relentless, grinding attrition had left tens of thousands dead in its wake. Imperial forces had been victorious after two years of fighting and earned a score of honours for the war banners. Victory had been won, but the cost had been high. The Thousand Sons sustained severe losses of eight hundred and seventy three battle-brothers of the 5th Fellowship, effectively wiping them out as a functioning unit. This forced Magnus to reduce his Legion from ten Fellowships to the Pesedjet, the nine Fellowships of Prosperine antiquity.
 * Great Crusade, 28/16-Aghoru Campaign (Cicra 200.M31) - Compliance action carried out by the Thousand Sons Legion that was achieved through diplomacy; secondary combat against apparent warp corruption.
 * Great Crusade, Ark Reach Cluster (Circa 200.M31) - This was a compliance action achieved by the Thousand Sons working with elements from the Space Wolves and the Word Bearers Legions. The return of the dreaded mutational flesh-change occurred at the conclusion of this campaign and helped to bring on the eternal emnity between the Space Wolves and the Thousand Sons.

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 two specialist units created - the elite Scarab Occult Terminators and the Hidden Ones of the Scout Auxillia.
 * 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.


 * 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 Legion 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 they 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, which represented the most perfect and 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 Legion 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 5 Cults of the Thousand Sons Legion were as follows:
 * Athanaeans - The Athanaeans 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 which allowed them 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 (manipulate 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 are 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. 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 theImmaterium. 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, falling one by one to the strain until the 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 Prosperor, 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 - Primarch of the Thousand Sons.
 * Ahzek Ahriman - Former Chief Librarian of the Thousand Sons and Captain of the 1st Fellowship and Magister Templi of the Corvidae Cult.
 * Ahtep - Founder of the Raptora Cult.
 * Amon - Captain of the 9th Fellowship and Equerry to Magnus. Founder of the Corvidae Cult and its first Magister Templi.
 * Ankhu Anen - Guardian of the Great Library of Prospero and member of the Corvidae Cult.
 * 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 vile Orks.
 * Auramagma - 8th Fellowship Captain and Pyrae Cult member.
 * 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.
 * Hastar - A member of the 1st Fellowship; Hastar is particularly notable for being the first member of the Legion to fall victim to the flesh-change since 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 called Hastar but it remains unclear whether or not this is one and the same person.
 * Mordant Hex - Sorceror Lord of the Thousand Sons
 * Imhoden - Co-founder of the Pavoni cult along with Hastar. It is unclear whether one or both of the founders were considered Magister Templi.
 * Karlsen - Sorceror of the Thousand Sons
 * Khalophis - 6th Fellowship Captain and Magister Templi of the Pyrae Cult.
 * Luxan-htep - Co-founder of the Rapora Cult along with Ahtep. It is unclear whether one or both of the founders were considered Magister Templi.
 * Hathor Maat - 3rd Fellowship Captain and Magister Templi of the Pavoni Cult.
 * Madox - Chaos Sorcerer.
 * Memphia - Co-founder of the Pyrae Cult.
 * Mhotep - Fleet Captain of the Thousand Sons' Strike Cruiser Waning Moon (Pre-Heresy); killed in action before the fall of the Thousand Sons to Tzeentch.
 * Phanek - Founder of the Athanaeans Cult.
 * Sobek - Practicus to Ahriman and Corvidae Cult member.
 * Thothmes - Co-founder of the Athaneans Cult along with Phanek. It is unclear whether one or both of the founders were considered Magister Templi.
 * Phosis T'Kar - Captain of the 2nd Fellowship and Magister Templi of the Raptora Cult.
 * Phael Toron - 7th Fellowsip Captain and member of the Raptora Cult.
 * Uthizzar - 5th Fellowship Captain and Magister Templi of the Athaneans Cult.

Legion Fleet
During the Horus Heresy the Thousand Sons are known to have possessed the following vessels:2
 * Ankhtowe (Battle-Barge) (pre-Heresy)
 * Kymmeru (Battle-Barge) (pre-Heresy)
 * Photep (Battle-Barge) - Flagship (pre-Heresy)
 * Scion of Prospero (Battle-Barge) (pre-Heresy)
 * Waning Moon (Strike Cruiser) - Commanded by Fleet Captain Mhotep. (pre-Heresy)

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 badge that Thousand Sons Chaos Marines bear upon their shoulder pads is the ouroboros, but used to be a red 'M', for Magnus. 'M' is also the Roman numeral that stands for one thousand, and this is the source of their Legion's name. Just before the Heresy, this badge was altered into a red flaming circle, which became the precursor to the Post-Heresy badge. This does not mean that after the original thousand Marines were created as gene-sons of Magnus by the Emperor, that others were not made during the course of the Great Crusade. Often Legions were usually comprised of ten thousand standing Space Marines and the Thousand Sons were no different at the height of the Imperium's expansion before the Horus Heresy.