Constantine XI Palaiologos
Theodore II Palaiologos was a son of the Byzantine Emperor Manuel II Palaiologos and his wife Helena Dragaš. His maternal grandfather was the Serb prince Constantine Dragaš. His brothers included emperors John VIII Palaiologos and Constantine XI Palaiologos, as well as Demetrios Palaiologos and Thomas Palaiologos, despots in the Despotate of Morea, and Andronikos Palaiologos, despot in Thessalonica.