The Dark Marches Crusade was but one of many military campaigns launched in 610.M36 within the Segmentum Tempestus. Having benefitted from some centuries of respite, known to later historians as the period of "the Rising Storm," the armies of the Segmentum launched several interlinked campaigns and Imperial Crusades in the ultimate goal to secure, strengthen and expand the Imperium's borders. The Dark Marches Crusade marks the final step of these expansionist efforts, claiming many worlds in the name of the Emperor of Mankind. Alas, during the following millennia, those worlds conquered by the Dark Marches Crusade where increasingly lost, the latest case being the fall of the Orpheus Sector in the still-ongoing Orphean War. With much of this Crusade's former conquests now lost to the enemy