Pope Pius II (Latin: Pius PP. II, Italian: Pio II), born Enea Silvio Bartolomeo Piccolomini (Latin: Aeneas Silvius Bartholomeus; 18 October 1405 – 14 August 1464), was head of the Catholic Church and ruler of the Papal States from 19 August 1458 to his death. Aeneas Silvius was an author, diplomat, and orator, and private secretary of Antipope Felix V and then the Emperor Frederick III, and then Pope Eugenius IV. He participated in the Council of Basel, but left it in 1443 to follow Frederick, whom he reconciled to the Roman obedience. He became Bishop of Trieste in 1447, Bishop of Siena in 1450, and a cardinal in 1456. He was a Renaissance humanist with an international reputation. Aeneas Silvius' longest and most enduring work is the story of his life, the Commentaries, which is the only autobiography of a pope ever to have been published. It appeared posthumously, in 1584, 120 years after his death. Source: Wikipedia (en)