Pope Callixtus III, born Alfons de Borja, was head of the Catholic Church and ruler of the Papal States from 8 April 1455 to his death in 1458.
He is the most recent pope to have taken the pontifical name of "Callixtus" upon his election. He was also responsible for the retrial of Joan of Arc that saw her vindicated. A member of the powerful Borgia family, Callixtus III was the uncle of Pope Alexander VI, whom he appointed to the College of Cardinals.
Callixtus III died on 6 August 1458. His remains were transferred in 1586 and again in 1610 with the remains of Pope Alexander VI to Santa Maria in Monserrato. His remains were transferred once more on 21 August 1889 in the chapel of San Diego.