Eugene IV, 1383–1447, pope (1431–47), a Venetian named Gabriele Condulmer; successor of Martin V. He was of exemplary character and ascetic habits. Gregory XII, his uncle, made him cardinal (1408). The first part of Eugene's reign was beset with the difficulties created by the Council of Basel (see Basel, Council of), which began just after his election. Eugene at first opposed the council in its antipapal acts, but after he had been driven by rebellion from Rome into exile at Florence (1434) he was disposed to conciliate. Finally in 1437 he removed the council to Ferrara. Antipapal leaders refused to move, and the council, now in heresy, continued at Basel. It declared Eugene deposed and elected Amadeus VIII of Savoy antipope (as Felix V). It attracted little support, however. Meanwhile the Council of Ferrara-Florence met and proclaimed (1439) the reunion of Eastern and Western churches. Abortive as this union proved to be, it greatly enhanced the papal prestige, and in 1443 Eugene returned to Rome from Florence. Eugene was succeeded by Nicholas V.
See biography by J. Gill (1961).