Vigilus is an Imperial Hive World in the Vigilus System of the Segmentum Obscurus that represents the terminus of a key route — the Nachmund Gauntlet — through the Great Rift into the Imperium Nihilus.
As a result, Vigilus has become a heavily contested strategic location and the source of conflict between several of the different starfaring species and factions of the Milky Way Galaxy in the early 42nd Millennium.