The 1458 papal conclave (August 16–19), convened after the death of Pope Callixtus III, elected as his successor Cardinal Enea Silvio Piccolomini who took the name Pius II.

[1] He was severely criticized due to his nepotism and devotion towards his compatriots of Catalonia, making him very unpopular among the rather xenophobic Roman populace.

After the Pope's death an open revolt against him broke out and some of his partisans (e.g. his nephew Pedro Luis de Borja) had to flee Rome.

Pierre de Foix was the last surviving cardinal of the Great Western Schism and was elevated by Pisan Antipope John XXIII.

But Cardinal Capranica died suddenly on August 14, 1458, two days before the beginning of the conclave, leaving his party in great confusion.

Initially they subscribed to the conclave capitulation, which obliged the elect to continue the crusade against the Ottoman Empire and to give more welfare to poorer cardinals.

On August 18 in the evening he was certain that he would obtain at least eleven votes on the following morning[6] But the opposite Italian party also lost no time.

On September 3, 1458, he was solemnly crowned on the steps of the patriarchal Vatican Basilica by Cardinal Prospero Colonna, protodeacon of S. Giorgio in Velabro.