They were exceptional by way of their perfection there were no recorded rejections or abnormalities amongst the “alpha” intake, and the Legion benefited from recruits from all over Terra.

The Ultramarines were, as with their brother legions, founded on Terra at the end of the Unification Wars. This, in many ways, makes the betrayal they endured far more bitter. The Ultramarines are a fighting force without peer, true, but they are also an image of civilisation, and what Humanity under wise leadership could be.

They are the lords of the Five Hundred Worlds, the lapis-blue guardians of a shining Elysium forged by the brilliance of Robute Guilliman among the carnage of the Great Crusade. The UItramarines are the Thirteenth Legion Astartes, but to simply label them as such is, I feel, to do them a disservice they are more than that. “At the outset of the cataclysmic civil war created by the treachery of Horus and the machinations of the dark powers of the Warp, the XIII Legion, the Ultramarines, stood as one of the single, most powerful military forces in the Imperium.” In this article – the fourth posted on Goonhammer – we visit the Five Hundred Worlds of Ultramar, and look at their masters – the Ultramarines.

The Space Marine Legions of the First Founding make up the core factions and conflict of the Horus Heresy. The Horus Heresy: Legion Overview – The Ultramarines

Horus heresy word bearers