John XXIII, 1881–1963, pope (1958–63), an Italian (b. Sotto il Monte, near Bergamo) named Angelo Giuseppe Roncalli; successor of Pius XII. He was of peasant stock. Educated at Bergamo and the Seminario Romano (called the Apollinare), Rome, he was ordained in 1904. While secretary to the bishop of Bergamo (1904–14) he wrote scholarly works, among them a life of St. Charles Borromeo (completed in 5 vol., 1936–52). Called up for service in World War I, he was first in the medical corps and was later a chaplain. After the war he held posts in Rome and reorganized the Society for the Propagation of the Faith. In 1925 he was made archbishop and sent as Vatican diplomatic representative to Bulgaria. Later he was representative in Turkey and Greece, and in 1944 he was named papal nuncio to France. There he acted as mediator between the conservative churchmen and the more socially "radical" clergy; he gained popularity. In 1953 he was made cardinal and the patriarch of Venice. He was elected pope Oct. 28, 1958. As pope, he put reforms into practice: He laid stress on his own pastoral duties as well as those of other bishops and the lesser clergy; he was active in promoting social reforms for workers, the poor, orphans, and the outcast; he advanced cooperation with other religions (among his innumerable visitors were many Protestant leaders, the head of the Greek Orthodox Church, the archbishop of Canterbury, and a Shinto high priest). In Apr., 1959, he forbade Roman Catholics to vote for parties supporting Communism, but his encyclical Mater et Magistra —a vigorous social document issued July 14, 1961, just 30 years after Pius XI's Quadragesimo Anno —advocated social reform, assistance to underdeveloped countries, a living wage for all workers, and support for all socialist measures that promised real benefit to society. Pope John XXIII almost doubled the number of cardinals, making the college the largest in history to that point. On Jan. 25, 1959, he quietly announced the intention of calling an ecumenical council to consider measures for renewal of the church in the modern world, promotion of diversity within the encasing unity of the church, and the reforms that had been earnestly promoted by the ecumenical movement and the liturgical movement (see liturgy). The convening of the council on Oct. 11, 1962, was the high point of his reign (see Vatican Council, Second). His heartiness, his overflowing love for humanity individually and collectively, and his freshness of approach to ecclesiastical affairs made "Good Pope John" one of the best-loved popes of modern times. He was succeeded by Paul VI. John XXIII was beatified in 2000 by Pope John Paul II.
See his memoirs, Journal of a Soul (tr. 1964, rev. ed. 1999) and Letters to His Family (1970); biographies by M. Trevor (1967) and L. Elliott (1973).