Following the Age of Strife, with humanity teetering on the brink of annihilation, the Emperor of Mankind unleashed a weapon of unimaginable power. His Space Marines. These mighty warriors, forged in the furnace of war, were marshalled together into the twenty Legions known as the First Founding. In the Era Indomitus, nine of the warrior brotherhoods remain true. Once Legions, now Chapters, they stand defiant as mankind's bulwark against the heretic, the xenos and the daemon.