The Emperor of the Terran Dominion is a title created by Arcturus Mengsk in March, 2500 after the Fall of Tarsonis. The holder of the title is the supreme ruler Terran Dominion. During the Defenders of Man Insurgency, pressure from the Defenders of Man caused Emperor Valerian Mengsk to state his intention to step down as Emperor of the Terran Dominion, leaving the state of the throne uncertain.