Theodore Svetoslav of Bulgaria

Theodore Svetoslav, son of Tsar George Terter I, spent his youth as a hostage in Byzantium and the Golden Horde. After his father divorced his mother, they were sent to Nicaea; Patriarch Joachim III arranged Theodore's release in 1285.

In 1299 he backed the Mongol prince Chaka's seizure of Tarnovo, but in 1300 he strangled Chaka and seized the crown. As tsar he ended Mongol suzerainty, executed Patriarch Joachim III for treason, captured Mesembria and Anchialos in 1304, and routed Michael IX Palaiologos.

The peace of 1307 was sealed by his marriage to Theodora, Michael IX's daughter. He died in 1322, leaving the throne to his son George Terter II.