D'deridex was the male Romulan who served as Praetor of the Romulan Star Empire during the mid-2150s in the run-up to the Earth-Romulan War. (ENT novel: Kobayashi Maru) Under Praetor D'deridex's administration, the Romulan Star Empire adopted a policy of covert destabilization and expansionism, seeking to control the government of the Confederacy of Vulcan through the use of a puppet government under Adminstrator V'Las (ENT episode: "Kir'Shara"), inciting war between the Andorian Empire and Tellar Prime (ENT episode: "Babel One"), and through the use of remote-hijacking technology on Coalition of Planets-allied ships. (ENT novel: Kobayashi Maru)