Pope Pius II (Latin: Pius PP. II, Italian: Pio II), born Enea Silvio Bartolomeo Piccolomini (Latin: Aeneas Silvius Bartholomeus) was Pope from 19 August 1458 to his death in 1464. He was born at Corsignano in the Sienese territory of a noble but impoverished family. His longest and most enduring work is the story of his life, the Commentaries, which is the only autobiography ever written by a reigning pope.
Calixtus III died on 6 August 1458. On 10 August, the cardinals entered into a papal conclave. According to Aeneas' account, the wealthy cardinal Guillaume d'Estouteville of Rouen, though a Frenchman and of apparently exceptionable character, seemed certain to be elected. In a passage of his own history of his times, long excerpted from that work and printed clandestinely in the Conclavi de' Pontifici Romani, Aeneas explained how he frustrated the ambitions of d'Estouteville. It seemed appropriate to Aeneas that the election should fall upon himself: although the sacred college included a few men of higher moral standards, he believed that his abilities made him most worthy of the papal tiara. It was the peculiar faculty of Aeneas to accommodate himself perfectly to whatever position he might be called upon to occupy, and he now believed that he could exploit this adaptability to assume the papacy with appropriate success and personal character. After a minimum of intrigue among the cardinals, he was able to secure enough votes for his candidacy after the second ballot to be elected unanimously. He was crowned Pope on 3 September 1458.
He died on 14 August 1464, and was succeeded by Pope Paul II. Pius II's body was interred in the church of Sant'Andrea della Valle in Rome, while an empty cenotaph was built in St. Peter's Basilica. Later, the cenotaph was moved to Sant'Andrea as well.