 Nicholas V having died in early 1455, the new Pope Calixtus III elevated James to a cardinal-deacon of the Church (despite not having the requisite 30 years of age for the office), assigning him the titular diaconate of Santa Maria in Portico Octaviae, soon substituted for the diaconate of Sant'Eustachio.Callixtus III also gave James the Bishopric of Paphos, in Cyprus, where his brother, John, had married Charlotte of Lusignan, Princess of Cyprus.Following the death of Callixtus III, James of Portugal participated in the conclave that elected Pius II as the new pope.