A popular chapter of the Adeptus Astartes from the Warhammer 40k franchise, distinguished by their bright red armor.
One of the original Space Marine legions, led by their Primarch, Sanguinius. While they and most of their successor chapters are normally among the more compassionate groups of Space Marines, they suffer from two distinct flaws: the Red Thirst, which temporarily fills them with an insatiable bloodlust, and the Black Rage, in which a Marine suffers a lasting flashback to the death of Sanguinius and goes completely berserk. The latter is often incurable and sufferers are organized into "Death Companies".