JOHN VIII PALAEOLOGUS

born 1390 died Oct. 31, 1448, Constantinople Byzantine emperor who spent his reign appealing to the West for help against the final assaults by the Ottoman Turks on the Byzantine Empire. Son of Manuel II Palaeologus, John was crowned co-emperor with his father in 1421 and succeeded him in July 1425. He ruled the area immediately surrounding Constantinople, while his brothers governed remnants of the fragmented empire in the Greek Peloponnese and in the districts on the Black Sea. Constantinople was besieged in June 1422 by the Turkish sultan Murad II, and when the Turks took Thessalonica (modern Thessalonki, Greece) in March 1430, John turned to the West for help. In 1437 he went to Italy, where he brought about a union between the Byzantine and Latin churches at the Council of FerraraFlorence (1439). Western efforts against the Turks failed, and the union stirred dissension among the Byzantines, who refused to submit their church to the papacy. John's spirit was broken, and intrigues over the succession, coupled with news of the Turkish victory over the Hungarians in the Second Battle of Kosovo in October 1448, hastened his death.