The Overseers were a race of sentient machines encountered on the world of Dahinta by the Luna Wolves Space Marine Legion's 63rd Expeditionary Fleet during the Great Crusade in the late 30th Millennium. The Luna Wolves would go on to fight a brutal genocidal campaign against this machine race. One of the Emperor's longest-standing commands was that no sentient machines could be allowed to exist, for they had nearly caused the extinction of Mankind when they had rebelled against their human masters during the Dark Age of Technology. Despite heavy casualties amongst the Astartes, the thinking machines were ultimately wiped from the face of Dahinta by the savagery of the Space Marines.