Mordur was an admiral in the Imperial forces throughout the Galactic Civil War. Following the Empire's significant loss at the Battle of Endor in 4 ABY, Mordur participated in a scheme designed to destabilize the Alliance of Free Planets' hold on Vandelhelm, a planet crucial for its shipbuilding capabilities. Operating from a transformed drone barge, Mordur collaborated with Orrk, who was the Guildmaster of the Metalsmiths Guild, with the goal of assassinating the "Venerated Ones," who were two young members of the royal family. This would grant them complete authority over Vandelhelm's metal trade. However, their strategy was thwarted by the skillful piloting abilities of Alliance operative Han Solo, who brought the Venerated Ones to safety on Vandelhelm and killing Orrk after revealing his betrayal. Mordur then retaliated by directing Vandelhelm's drone barge fleet to crash into the star of the system, but Solo successfully intervened to stop this plan too.
Mordur was introduced as a villain in Star Wars (1977) 98, which was written by Archie Goodwin, with illustrations by Al Williamson, and it was published in 1985.