After the death of Nicolas V. the choice of the cardinals fell upon Alfonso Borgia, who took the name of Calixtus III. [Sidenote: Calixtus III., 1455-1458.] He was a native of the Aragonese province of Valencia, and had been rewarded with the cardinalate for services rendered to the papacy in negotiations with Alfonso V. Although over seventy years of age, Calixtus showed creditable energy in urging the princes of Europe to war against the Turks, and he had the consolation of hearing of the signal victory of John Hunyadi, when Mohammed II. was repulsed from the walls of Belgrad in 1456. But the pontificate of Calixtus is mainly noteworthy for the elevation of a relative who was destined to involve the papacy in the gravest scandals. Nepotism was a natural result of the secular aims of the fifteenth century popes. As long as the popes had been the active heads of Christendom their energies were fully employed in carrying out a great task. But they were now little more than temporal princes, and their position differed from that of other princes in the impossibility of transmitting their power to a dynasty, and in the brief period of rule which was possible for men elected in advanced years. Hence there was a serious temptation to the popes to aggrandise their relatives at the expense of the Church or of neighbouring princes, and thus to confer those advantages upon their family which a secular prince could bring about by the normal action of hereditary succession. Calixtus had three nephews, the sons of a sister and a man called Lenzuoli. These young men were allowed to take the maternal name of Borgia, and their interests were vigorously forwarded by their uncle. Two were appointed cardinals, to the great scandal of the College and of Roman opinion; and one of these, Rodrigo Borgia, became the notorious Pope Alexander VI. The third nephew received the title of duke of Spoleto, and the offices of Gonfalonier of the Church and prefect of Rome.