War for the Andromax System
The War for the Andromax System occured during the 8th Black Crusade, when a combined force of Night Lords and Iron Warriors captured the Imperium's Andromax System. Once word of this reaches the Adeptus Custodes, they declare the System's capture to be a direct threat to Terra and make plans to destroy the traitors. They know however, that they will need aid to do this and ask the Fabricator-General Uixot, for Mars assistance in the endeavor. The notoriously insular Uixot at first refused, but agreed to help after a diplomatic mission from the Adeptus Custodes met with him and stroked his ego. Mere months later, a combined force of the Minotaurs Chapter, Adeptus Mechanicus and Custodians from the Dread Host, annihilate the traitors and reclaim the Andromax System for the Imperium.