He wears black glasses and smokes cigars from Mushroom Kingdom. He was noticed in many wars, where he captured some cities and connected them to Gamelon.
Later he wanted to conquer Hyrule with Ganon, but Ganon was so stupid, so Duke was arrested. He had to scrub all the floors in Hyrule before the could talk about mercy, but he ordered his slaves to scrub instead of him.
He then sneaked away when Nobody was watching, and ran back to his house crying like a baby. He ordered 16,278,577,157,966.482 guards to guard his castle. He didn't have that many guards, but ordering that much reassured him anyways.