Slaughter of Malphi IX

The Slaughter of Malphi IX was a campaign launched by the Sons of Damnation Renegade Chapter against the Imperial world of Malphi IX. Three Space Marine Chapter answered the calls to arms, including the Angels Herald, Emperor's Phantoms and Wandering Serpents, to halt the Chaostic onslaught.

History
The Sons of Damnation assaults the world of Malphi IX, intent on making the vibrant Imperial world into a daemonic realm of Chaos. Summoning daemonic allies from the Immaterium, local sector Imperial Guard forces are hard pressed to halt the daemonic onslaught, and soon send a desperate astropathic distress signal. Their desperate pleas are answered in the form of an Imperial strike force comprised of three Loyalist Space Marine Chapters, including the Emperor's Phantoms, Wandering Serpents and the Angels Herald, who were sent to wipe out the traitorous Sons of Damnation from the planet's surface.

An intense battle raged for three weeks between the Imperial forces and the Forces of Chaos. All three loyalist Chapters took substantial losses, especially the Angels Herald, who only had 300 surviving Battle-Brothers by the battle's end. Sensing their impending defeat, the Sons of Damnation summon Warp portals and departed the planet's surface. The resultant fighting and the release of the Ætheric powers of the Warp, cause Malphi IX to be engulfed in baleful darkness for over a century.