Pics of the Week happen every Tuesday where I share from my Warhammer pic library. I collect these all the time from all over, and sharing them is just fun.
The Thousand Sons were Legion XV of the original twenty Space Marine Legions. Their Primarch is Magnus, oft called Magnus the Red. The Legion turned traitor during the Horus Heresy, after which it relocated to the Planet of Sorcerers in the Eye of Terror and dedicated itself to the Chaos God of change, sorcery and magic, Tzeentch. For a time it appeared that Tzeentch protected the Thousand Sons from the corruption and fragmentation that most of the other Traitor Legions underwent, but eventually the Legion went through a crisis of mutation and de-evolution, seemingly at the wish of their patron-God. Aghast at this development, their chief sorcerer, Ahriman, cast a powerful spell designed to render the Thousand Sons immune to the warping effects of Chaos. While the spell succeeded in this goal, it had an unforseen consequence of transforming the mutated Thousand Sons into little more than mystically animated suits of armour barely capable of being termed as anything more sentient than automata.
With the only surviving cognisant members being those incredibly strong in heretical psychic powers, the Thousand Sons are now a legion of ghosts led by the damned.