Sixtus IV

(Francesco della Rovere; r. 1471-1484)

   Sixtus IV was a Franciscan who served as the general of the order in 1464. In 1467, he received the cardinalate at the recommendation of the Greek Cardinal Basilius Bessarion who admired him for the theological treatises he wrote on divisive questions among Franciscans and Dominicans. When Pope Paul II died suddenly in 1471, Sixtus emerged as the favorite candidate during the conclave, his election ensured by his nephew Pietro Riario's promises of preferred treatment to the attending cardinals. Sixtus' reign was punctuated by modest successes in crusades against the Turks, strained relations with Louis XI who required that papal decrees receive royal approval prior to their publication in France, negotiations with Russia for the unification of its church with that of Rome, and their support in the fight against the Turks. Sixtus also set up the Spanish Inquisition in 1478 and confirmed Tomás de Torquemada as grand inquisitor.

   On the domestic front, Sixtus gave added privileges to the mendicant orders and he approved the Feast of the Immaculate Conception. He showered his family with favors, including his two nephews, Pietro Riario and Giuliano della Rovere, both of whom he appointed to the cardinalate soon after his election to the throne. In 1478, Sixtus was involved in the Pazzi Conspiracy against the Medici, which resulted in war against Florence (1478-1480). In 1482, he also involved himself in the war between Venice and Ferrara and, in the following year, he turned on Venice by imposing an interdict (suspension of public worship and withdrawal of the Church's sacraments) on the city.

   Sixtus also committed himself to the aggrandizement of the papacy. To this effect, he called leading masters to Rome to work on the Sistine Chapel decorations, among them Pietro Perugino, Domenico del Ghirlandaio, and Sandro Botticelli. He was also the patron of Melozzo da Forli, whose experiments in perspective changed the history of ceiling painting, and Antonio del Pollaiuolo, who rendered his tomb in St. Peter's. Sixtus' restoration campaign, which included the widening and repaving of roads, the refurbishing of the Ospedale di Santo Spirito, and the building of Santa Maria della Pace, his family's final resting place, has earned him the recognition of having transformed Rome from a medieval to a Renaissance city.