DO YOU HEAR THE VOICES TOO?

The Sons Of Horus were one of the nine "First Founding" chapters that turned to the taint of chaos, however they are mostly known as The Black Legion after Horus' lieutenant Abaddon The Despoiler.

The Chaos Marine Legions were nine of the twenty original "First Founding" Legions of Space Marines who fought in the Great Crusade for the Imperium of Man. At this time the Primarch Horus and the Luna Wolves were corrupted by Chaos and instigated the galaxy-wide civil war known as the Horus Heresy.