Yu'Vath

The Yu'vath were an ancient and corrupted alien-empire that inhabited the Calyx Expanse two standard millenia ago, during the Angevin Crusade. These evil xenos were no more than a twisted servants of the warp, they built an empire on a foundation of dark sorcery, soul-slavery and daemon worship. For years the Crusade fought a bloody war against them, slowly pushing them back in the face of massed slave armies and vile warp-technology. Finally Saint Drusus himself struck the final blow and ended their domination over the Calyx Expanse. What was left of their worlds and artefacts were destroyed and their locations purged from the Imperial records and over time their existence was slowly forgotten. Whispers in the Expanse persist however that they were never truly defeated and there are Yu'vath worlds still hidden deep within the darkness of the Calixis Sector.