Fra Angelico had been called in about 1445 to Rome, where he has continued to paint.

(Except for the private chapel of Pope Nicholas V in the Vatican, which contains Angelico's frescoes of scenes from the lives of Saint Stephen and Saint Lawrence, all the buildings he worked on there have been destroyed.).

At his death in Rome at fifty-five on February 18, 1455, he is considered the most influential of all contemporary Florentine painters.

The fall of Constantinople to the hands of the Ottomans is a blow to Christianity and the established business relations linking with the east.

In 1455, Pope Nicholas issues the bull Romanus Pontifex, reinforcing previous Dum Diversas (1452), granting all lands and seas discovered beyond Cape Bojador to King Afonso V of Portugal and his successors, as well as trade and conquest against Muslims and pagans, initiating a mare clausum policy in the Atlantic.

At the death of Nicholas on March 24, 1455, seventy-six-year-old Alfonso de Borgia, a member of a noble family from Valencia, succeeds him on April 8 as Callistus III, 1455.

Callixtus canonizes his late countryman, the Valencian Dominican friar Vincent Ferrer, on June 8.