Johannes Bessarion, or Basilius (c. 1395-1472), titular patriarch of Constantinople, and one of the illustrious Greek scholars who contributed to the great revival of letters in the 15th century, was born at Trebizond, the year of his birth being variously given as 1389, 1395 or 1403.

He was educated at Constantinople, and in 1423 went to the Peloponnese to hear Gemistus Pletho expound the philosophy of Plato. On entering the order of St Basil, he adopted the name of an old Egyptian anchorite Bessarion, whose story he has related. In 1437 he was made archbishop of Nicaea by John VII Palaeologus, whom he accompanied to Italy in order to bring about a reunion between the Greek and Latin churches (which have been separated since the Great Schism of 1054) with the object of obtaining help from the West against the Turks.

The Greeks bitterly resented his attachment to the party which saw no difficulty in a reconciliation of the two churches. At the councils held in Ferrara and Florence Bessarion supported the Roman church, and gained the favour of Pope Eugenius IV, who invested him with the rank of cardinal.

From that time he resided permanently in Italy, doing much, by his patronage of learned men, by his collection of books and manuscripts, and by his own writings, to spread abroad the new learning. He held in succession the archbishopnic of Siponto and the bishoprics of Sabina and Frascati.

In 1463 he received the title of Latin patriarch of Constantinople; and it was only on account of his Greek birth that he was not elevated to the papal chair. For five years (1450-1455) he was legate at Bologna, and he was engaged on embassies to many foreign princes, among others to Louis XI of France in 1471. Vexation at an insult offered him by Louis is said to have hastened his death, which took place on November 19 1472, at Ravenna.

Bessarion was one of the most learned scholars of his time. Besides his translations of Aristotle's Metaphysics and Xenophon's Memorabilia, his most important work is a treatise directed against George of Trebizond, a violent Aristotelian, entitled In Calumni atorem Platonis. Bessarion, though a Platonist, is not so thoroughgoing in his admiration as Gemistus Pletho, and rather strives after a reconciliation of the two philosophies. His work, by opening up the relations of Platonism to the main questions of religion, contributed greatly to the extension of speculative thought in the department of theology. His library, which contained a very extensive collection of Greek manuscripts, was presented by him to the senate of Venice, and formed the nucleus of the famous library of St Mark.

See AM Bandini, Dr Vita et Rebus Gestis Bessarionis (1757); H Vast, Le Cardinal Bessarion (1878); E Legrand, Bibliographie Hellinique (1885); G Voigt, Die Wiederbelebung des klassischen Altertuns, ii. (1893); on Bessarion at the councils of Ferrara and Florence, A Sadov, Bessarion de Nicée (1883); on his philosophy, monograph by A Kandelos (in Greek, Athens, 1888); most of his works are in Migne, Patrologia Graeca, clxi.