Index Astartes: Thousand Sons-Terror from the Warp
"My sons we are the Imperium's guiding light, and you must remain so. Continue to bear the beacon of knowledge forwards across the galaxy freeing all of mankind from the chains of ignorance. However, you cannot spread knowledge to the people of the Imperium without protecting them and thus you my sons must tear every loathsome traitor from their holes. Shatter the respites that the heirs of slaughter lurk behind and purify them with the flames of knowledge. Sear the flesh of the World Eater's from their bones, cast the Sons of Horus into the pyres of hope, reduce the Word Bearers into atoms, scour the White Scars from this reality, flay the Night Lords with the warp, burn the Night Hunter's shadows, and purge the corrupting rot of the Ultramarines. Farewell my son. AVE IMPERATOR!" Magnus the Red before being interned in the Golden Throne foe the first time.
Origins
"This is the reason that we fell our infighting our loathing our betrayal we must stand together if we wish to rebuild Prospero." Magnus the Red during his debate with the Elders of Tizca
"Any last words before I scorch your soul from existence." Magnus the Red to the last soldier of the Reactionaries.
The world of Prospero had been hard hit by the Age of Strife with the high population of Pyskers allowing demons to tear themselves free from the depths of the warp and set the planet ablaze. The vast majority of the planet was lost to strange beasts from the warp with only a few scattered cities remaining free the largest of these was the city of Tizca. Dominated by libraries and the pursuit of knowledge the city had unleashed experimental technologies to hold the warp off and had survived for millennia free. It was in this city that Magnus the Red Primarch of the Thousand Sons landed.
The young Primarch knew how to wield the powers of the warp and within a year became the pinnacle of what Pyskers could achieve on Prospero but he delved to greedily and too deep and awoke something from the depths of the warp. Unleashing beasts that not even greatest schoolers of the age could comprehend Tizca was nearly wiped out and he only survived by unleashing his full force to kill the creature and only then he merely wounded it rather than kill it. Magnus the Red was thrown into a coma for a year and as he slept he was contacted by the Emperor throw the warp who warned him of what dwelt in the warps.
When he awoke he knew that he needed to unite Prospero for his father. The crusade he led was one of flame, faith, and anger. Nests of demons were seared into ash while the few soldiers of Tizca that had joined his cause secured the ruins of long forgotten cities. When he had purged the continent on which Tizca lay he returned to the city and demanded that the city bow to him and join him in his quest. The city declared for his crusade and he launched his final conquest of Prospero.
As he soldiers swept across the planet the horrors that they found sent many insane and those who did not lose their sanity abandoned their support for the crusade and gathered around a small group of reactionaries who loathed Magnus the Red and his crusade. When the last demon on Prospero was seared into ash they struck. Their entire force was gathered around Magnus the Red in an attempt to kill the Primarch and immediately eliminate the leadership. The Reactionaries were annihilated they were broken, and the vast majority surrendered, and the last soldier died in pool of their own waste as Magus the Red set them aflame. As the soul and bones crumbled to ash the Emperor descended from the heavens and the Imperium grew once more.
The Great Crusade
"This is an SOS distress call from the mining ship Red Dwarf. The crew are dead, killed by a radiation leak. The only survivors were Dave Lister, who was in suspended animation during the disaster, and his pregnant cat, who was safely sealed in the hold. Revived three million years later, Lister's only companions are: a lifeform who evolved from his cat, and Arnold Rimmer, a hologram simulation of one of the dead crew." A distress message retrieved by the Thousand Sons and promptly ignored
"I say Azheck the Xenos are putting up a much better fight this time." Magnus the Red when fighting against the Eldar.
During the Great Crusade, the Thousand Son focused heavily against groups with high levels of Pyskers due to Magnus's knowledge and Pyskic power allowing him to shred his enemies. The Thousands Sons soon became one of the legions most well-known for the slaughter of entire civilizations. Thousands of Imperial propaganda pieces show looming Astartes in billowing clouds of Pyskic flame surrounded by corpses of mutants, Xenos, or traitors. Their greatest victory was the Ark Reach Cluster Campaign alongside the Space Wolves.
The Ark Reach Cluster Campaign was a joint campaign conducted by the Space Wolves and the Thousand Sons a detachment of the Word Bearers were originally detached to the campaign, but they were delayed by a Waaaagh and unable to join the campaign. The campaign showed how well the two legions worked together with the Thousand Sons unleashing the might of the warp as the Space Wolves carved their way through legions of enemy soldiers. The greatest example was when Leman Russ and Magnus the Red fought together against a small warband of Orks that they had run into during the campaign. Fighting back to back the battle showed how close the two where and by the time that their legions arrived they had erected a wall of Ork ashes around them.
The Horusian Heresy
"Why Jaghatai why sell your soul to a daemon that has no reason to care or support you. Why?" Magnus the Red to Jaghatai Khan
"My sons we are under attack by traitors and monsters and we must fight back in the name of the Emperor. Ave Imperator!" Magnus the Red as the attack on Prospero attacked
During the Horusian Heresy the Thousand Sons only truly fought in a single battle that being Prospero for the remainder of the war they hunted the White Scars across the galaxy. From the ashes of Prospero, they hunted the Fifth Legion with the wrath of the Emperor and Imperium.
The battle of Prospero was one of the most important battles in the entire Horusian Heresy as it would effectively cripple two legions and seriously weaken a third. The battle began with the White Scars fleet attacking the orbital installations over Prospero, the destruction of the defensive positions would be quick and efficient following their destructions the landing began. The landings would allow the legion to tear across the planet slaughtering everyone that they could find and capturing the Astartes that they found the lesser cities on the planet until only Tizca was left and the battle of Tizca would be the deciding battle of the Thousand Sons involvement in the Heresy. The Thousands Sons had dug in preparing for the storm. The White Scars would launch three attacks before the lines were broken and the White Scars would flood through the city. Then the Emperors Children arrived, the Emperors Children managed to catch the Whites Scars on the flank with the ships holding orbit and continuing the bombardment of Prospero. The relief force would be divided in two one led by Fulgrim leading the relief on the ground while a force led by Lucius assaulting the flagship of the White Scars Swordstorm. The landing force would attack the assembled White Scars Hordes assaulting the Pyramid of Photep the defence commanded by Magnus the Red while the White Scars were unsuited to the urban combat required to the battle of Tizca. Fulgrim would catch the force in the side however too late to stop the ritual fuelling the destruction of the Imperial Webway wards and the ascension of Jaghatai Khan. Fulgrim and Magnus would attack the avian centaur together. The duel would be long the nine arms of the Daemon Primarch would prove useful. In space Lucius's force would take control of the Swordstorm however the damage used to take it alongside the broadsides from the White Scars ships caused the ships orbit to begin to decay. Lucius would notify his Primarch of this and the evacuation would speed up until Prospero was abandoned save for the loyalist forces equipped with teleport equipment and the White Scars. Fulgrim would order Swordstorm to ram the planet and Lucius obeyed. As the ship was about to connect the loyalists would teleport away, Jaghatai and the senior leadership of his legion would also escape while the rest would be wiped out by the shockwave of the ship.
The Scouring
"What demented fool would think that they could stand against me a son of the Emperor a guardian of mankind. I have sat upon the Golden Throne for a year I have been through unimaginable torment. You dare think you can stand against me? Tell Horus I say hello." Magnus the Red at the Third Battle of Cadia
"Leman I love you. But you need to stop drinking so much and get back to hanging out with me and the wolves. I know it's sad, but you have to push through." Magnus the Red to Leman Russ following the Emperor being permanently interned in the Golden Throne. M32
During the Scouring, the Thousand Sons focused on rebuilding and the Reclamation Project with no major battles against the traitors though the Space Wolves occasionally used them as auxiliaries against the Traitors. With the completion of the Reclamation Project the Legion focused purely on rebuilding their numbers so that they could provide forces to the Imperium against the forces of Chaos that the Scouring was purging from the Imperium. The only major battle that the Thousand Sons fought in during the Scouring was the Third Battle of Cadia which to call a battle is a lie greater than any other. There was three traitor Astartes that were promptly slaughtered by the Thousand Sons with Magnus the Red personally setting the last Astartes alight with a flick of his hand.
The Forty-First Millennium
"No matter what the traitors throw at us we shall stand for we are the light of knowledge we are the beacons of the Imperium. AVE IMPERTOR!" Azheck Ahriman before he vanished in M39
'AVE IMPERTOR!" Most common war cry of the Thousand Sons
The Thousand Sons are one of the most active legions in the millennium of Darkness but even they cannot hold of the mighty hosts of those who attack the Imperium, yet still they stand against the rising darkness and carve their names into its heart. While the Thirteenth Black Crusade seems to be coming from the Black Legions dominions within the Eye of Terror, the Ultramarines are gathering for a great plague war and the Zaherialn Crusade is gathering in the Kingdom of New Caliban despite these odds the Thousand Sons are gathering together preparing to fight for the Imperium, the ruins of Prospero, Magnus the Red, and the Emperor.
Organization
"Right so the Corvidae attack on the left with the Space Wolves while we attack through the centre with the Imperial Fists." Thousand Sons strategic planning prior to a battle M33
"Bloody Orks." Azheck Ahriman M36
The Thousand Sons are based around the five cults that the legionaries Pyskic power places them into as their Pyskic focused system of war lends themselves to basing their legion around Pyskic powers. Thus, when the Thousand Sons march to war clad in their red and gold Mark XXVIII 'Sekhmet' Power Armour the symbols on their left shoulders will determine the exact method of Pyskic force that will be used to slaughter their enemies. Thus, the blazing bolters and raging Pyskic powers that the Thousand Sons unleash in battle is often alongside the wild blood lust of the Space Wolves against their enemies in the name of the Emperor.
Primarch
"Magnus is a great mate he's smart, handsome and good at cooking though he does spend far too much time reading and that might have made him fall to Tzeentch or maybe Slaanesh." The opening line of the Chapter on Magnus the red in the Historical work The Primarchs: Heirs of the Emperor by Magnus the Red this particular chapter would be written by Leman Russ.
"Okay kids I'm going to be back when Leman does so I will return for the Wolftime." Magnus the Red leaving his legion.
Magnus the Red held massive Pyskic power able to scour entire planets clean of life within a few hours and sat upon the Golden Throne for three years to allow the Emperor to establish the base of the current Imperium. However, his power was not purely Pyskic due to his training by Vulkan and Leman Russ he was able to wield both the powers of the warp and mankind. He was a fervently anti-social Primarch spending the majority of his time reading or undertaking research on the warp. He was closest to his brother Leman Russ due to their shared issues over Gene-seed and joint social inability which is reflected in legions closeness even in this brutal age.
Homeworld
"Ah I've always love New Tizca nice short flight away from home." Bjorn the Fell Handed on New Tizca.
"In the name of the Emperor and Magnus the Red we are gathered here today to commemorate the great world of Prospero." Opening of the monthly commemoration of Prospero
The majority of the Thousand Son's homeworld of Prospero was destroyed in the Horusian Heresy and so the legion has been forced to transition to a fleet-based legion. Their flagship is the last remanent of Prospero itself a shard of the planet which is focused on the rebuilt city of Tizca. New Tizca as it is known is filled with civilians and military bases as the Thousand Sons managed to evacuate many of the civilians of Prospero and all of the contents of the Tizca libraries. New Tizca can be found in the Fenris system as it was dragged there by the Hrafnkel and Photep at the end of the Horusian Heresy where it has remained ever since.
Gene-Seed
"Apart from the Flesh Change we are complete fine. Stop looking at me like that Bjorn." Azheck Ahriman on the Thousand Sons Gene-seed
"As I was saying the most efficient way to clean your companion AGRTSDVJBAKUEDGCV GERVYCF" A Thousand Son falling to the Flesh Change during a lecture
The Gene-Seed of the Thousand Sons is problematic to say the least with the large problem of if they use to much of their inbuilt Pyskic power they may transform into chaos spawn this is known as the Flesh Change within the legion. However, after several centuries of work with the Space Wolves following the Horusian Heresy in the form of the Reclamation Project. While the Space Wolves chose not to form any successor Legions the Thousand Sons created the Golden Lions which is one of the more active legions in the current state of the Imperium. The Thousand Sons currently have around 50,000 Astartes bearing their gene-seed across the Imperium.