Abyssal Crusade

The Abyssal Crusade was a massive campaign undertaken in 321.M37, by the Imperium of Man into the hellish realm known as the Eye of Terror located in the Segmentum Obscurus. Saint Basillius passed judgement and 30 Space Marine Chapters were found wanting. The guilty embarked upon a penitent Crusade into the Eye of Terror, to purge those worlds stolen by the birth of the Dark Prince, Slaanesh.