Calixtus III (1378–1458)

Pope 1455–58. He was born in Aragon and trained there as a canon lawyer; he entered the service of Alfonso V in 1417, and followed him to Italy in 1432. He was made bishop of Valencia in 1429 and a cardinal in 1444, after having arranged a reconciliation between Alfonso and Pope Eugenius IV. His pontificate was dominated by attempts to organize a crusade, bringing him into conflict with his former employer, Alfonso.

The aged and bedridden candidate who emerged from the 1455 conclave as Calixtus III was very much a compromise choice; other candidates, such as Bessarion, aroused strong support but also strong opposition. If, though, he began his pontificate without many enemies, Calixtus subsequently alienated influential figures. The arrival of Catalans at the Roman curia caused consternation and accusations of nepotism, which only increased when Rodrigo Borgia, Calixtus's nephew, was created a cardinal. What is more, humanists became all too aware that the halcyon days of Nicholas V's cultural patronage were over – Calixtus considered the money better spent on crusading.