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. When Theodore was a little over ten years old, his father proclaimed him a despot (
despotēs) and appointed him to govern Morea after the death of his uncle
Theodore I Palaiologos in 1407. The nobleman
Nicholas Eudaimonoioannes was appointed as his tutor and regent until he came of age. The first period of his rule was a time of war against the Latin states in
Greece for the unification of
Morea. Theodore II's enemies in that period included the
Republic of Venice, which sent troops to impede his attempt to conquer
Patras. During Theodore's minority, his father Emperor Manuel II stayed in Morea and supervised its administration and defense, rebuilding the
Hexamilion wall across the
Isthmus of Corinth. A moment of drastic change in policy was his marriage to the Latin noblewoman
Cleofa Malatesta, arranged with the help of her uncle
Pope Martin V, who became Theodore's ally and supporter. In a letter from around the time of Manuel II's death (July 21, 1425), Pope Martin V called Theodore II emperor of
Constantinople (
ad Theodorum imperatorem constantinopolitanum) but the crown actually passed to his older brother John VIII. The war in Morea had started to go against the Byzantines and, under pressure from
Carlo I Tocco, the Count of
Kefalonia and ruler of
Epirus, the Despot demanded help from his brother John VIII. That help came in the form of reinforcements led by their brother Constantine, who became joint governor of Morea with Theodore II in 1428. The united efforts of the brothers contributed to the
naval victory at the
Echinades in 1427 and the conquest of Patras in 1430. On the other hand, Emperor John VIII declared Theodore's younger brother Constantine
regent of the empire during his voyage to
Florence in 1438, which emphasized his selection of Constantine as his intended heir. The next several years were marred by disputes with Constantine over the succession to the childless John VIII. In a compromise, Theodore II Palaiologos surrendered his claim to the throne in exchange for Constantine's domain (
appanage) of Selymbria (
Silivri) in 1443, where he died of plague five years later, in 1448, predeceasing his brothers. ==Family==