Theodore Svetoslav (Bulgarian: Тодор Светослав, Todor Svetoslav and also Теодор Светослав, Teodor Svetoslav) ruled as emperor (tsar) of Bulgaria from 1300 to 1322. The date of his birth is unknown. He was a wise and capable ruler who brought stability and relative prosperity to the Bulgarian Empire after two decades of constant Mongol intervention in the internal issues of the Empire. Theodore Svetoslav's reign began with the return of Southern Bessarabia to Bulgaria and a few years later he managed to defeat the Byzantines and retake most of northern Thrace occupied by them during the crisis. After 1307 he led peaceful policy towards all neighbours which resulted in expanded trade and economy.
Apart from his external and economic successes, Theodore Svetoslav dealt with the separatists among the nobility including his uncle. He persecuted the traitors who he thought were responsible for the Mongol interference and even the Patriarch, Joakim III, was executed.