Nov. 25, 1881: Born Angelo Giuseppe Roncalli in Sotto il Monte, Italy. He is the fourth of 14 children.
March 28, 1892: Enters the seminary at Bergamo, Italy.
1896: Admitted to the Secular Franciscan Order.
Aug. 10, 1904: Ordained as a priest in Rome's Piazza del Popolo.
1905: Appointed secretary to the new bishop of Bergamo.
May 7, 1915: Drafted into Italian military as a sergeant in the medical corps during World War I and becomes a chaplain.
1919: Named spiritual director of the Bergamo seminary.
November 1921: Appointed as the Italian president of the Society for the Propagation of the Faith by Pope Benedict XV.
March 19, 1925: Elevated to bishop by Pope Pius XI. Soon after, he is made apostolic delegate to Bulgaria.
Nov. 30, 1934: Appointed apostolic delegate to Turkey and Greece and titular archbishop of Mesembria, Bulgaria.
Feb. 10, 1939: Pope Pius XI dies. Nine days later, Roncalli's mother dies, but he is unable to attend her funeral during the papal mourning period.
Dec. 22, 1944: Named Apostolic Nuncio to France by Pope Pius XII.
Jan. 12, 1953: Appointed patriarch of Venice and raised to the rank of cardinal.
March 5, 1953: Takes possession of his new diocese in Venice.
Oct. 15, 1958: Is elected 261st pope. Takes the name John XXIII, affirming the status of Baldassarre Cossa as an antipope — he claimed the papacy for five years in 1410.
Jan. 29, 1959: Calls for a new ecumenical council, Vatican II, to modernize the Catholic Church.
Sept. 23, 1962: Is diagnosed with stomach cancer less than three years after being elected pope.
October 1962: Offers to mediate talks between John F. Kennedy and Russian leader Nikita Khrushchev during the Cuban Missile Crisis.
Jan 4, 1963: Becomes the first pope to be named Time magazine's "Man of the Year."
May 11, 1963: Is awarded the Balzan Prize for his engagement for peace efforts. The ceremony would be his last public appearance.
June 3, 1963: Dies of peritonitis caused by a perforated stomach.
Dec. 3, 1963: Is posthumously awarded the Presidential Medal of Freedom by Lyndon B. Johnson.
Sept. 3, 2000: Is beatified, along with Pope Pius IX, by Pope John Paul II.
July 4, 2013: Pope Francis confirms that John XXIII is to be canonized.
SOURCE: The Vatican