The Knights of Blood are a warband of frenzied Chaos Space Marines of unknown origin who are most likely servants of the Blood God Khorne. They have been responsible for numerous massacres of Imperial populations including the ones carried out on the worlds of Cadon, Helka II, Obsus Prima and most recently on Ornsworld.
- Ornsworld Massacre (6690.999.M41) - Ornsworld came under attack by the Knights of Blood Chaos Space Marines during the 13th Black Crusade. In a cruel repetition of the horrors inflicted during the Gothic War nearly one thousand standard years earlier, over ninety percent of its population was massacred by these Traitor Marines before Imperial Guard reinforcements arrived to bolster the beleaguered planet's defences.
The Knights of Blood wear predominately blood-red coloured Power Armour with a black painted helm, backpack, greaves and legs. Areas of the armour painted in black that blend in with the red are given the appearance of dripping blood.
- Codex: Chaos Space Marines (4th Edition), pg. 20
- Codex: Imperial Guard (5th Edition), pg. 25