The Cardassian Twelfth Order was a military unit in the Cardassian Guard. The Twelfth Order was responsible for the defense of the Cardassian Union's rimward border. It saw frequent action against the Klingon Empire prior to the Dominion War. (The Dominion War Sourcebook: The Fires of Armageddon) During the Dominion War, this Order was headquartered on Sarpeidion V, one of the most heavily fortified planets in the Cardassian Union. (DS9: "Tacking into the Wind")