The father of Gregor von Muckenberger, Wilhelm was an officer in the Imperial Fleet. He commanded a fleet under Fleet Admiral Zeiten during the Second Battle of Tiamat, where he played an instrumental role in the defeat of the Free Planets Alliance genius tactician, Bruce Ashbey. Wilhelm saw the battle as an opportunity to avenge the recent death of his uncle, Fleet Admiral Keltring, who had long seen Ashbey as his nemesis.