Pius II (pī´əs), 1405–64, pope (1458–64), an Italian named Enea Silvio de' Piccolomini (often in Latin, Aeneas Silvius), renamed Pienza after him, b. Corsigniano; successor of Calixtus III. He attended the Council of Basel (1432; see Basel, Council of) as a layman and joined its secretariat. He was an opponent of Pope Eugene IV and in 1439 became secretary to Antipope Felix V (Amadeus VIII of Savoy). Meanwhile he gained a European reputation as a humanist scholar. Holy Roman Emperor Frederick III made him court poet and in 1442 secretary to the chancery in Vienna. In 1445, Piccolomini abandoned his rather dissipated way of life and began a new career. He went to Rome to submit to the pope and became (1446) a priest. He was made bishop of Trieste (1447), bishop of Siena (1449), and a cardinal (1456). As pope, Pius issued (1460) a bull condemning as heretical the conciliar theory (the doctrine that ultimate authority in the church rested in the general council rather than the pope). He was in continual dispute with Louis XI of France, who repeatedly attempted to control ecclesiastical affairs. He also quarreled with the Bohemian king George of Podebrad, rejecting (1462) the latter's petition that he confirm the Compactata (see Hussites). Such quarrels hampered him in achieving his aim of uniting the Christian rulers in a crusade against the Turks. He was about to set out on a crusade himself when he died. He was succeeded by Paul II. Pius did not patronize art or literature, despite his own literary interests and considerable literary talents. Of his works the most useful is his autobiography, the only one written by a pope.
See L. C. Gabel, ed., Pius II: Memoirs of a Renaissance Pope (1959, repr. 1962); R. J. Mitchell, The Laurels and the Tiara (1962).