Among the popes of the Renaissance era, few left a more lasting physical and institutional imprint on Rome than Sixtus IV. Born Francesco della Rovere on July 21, 1414, in Celle Ligure, a town near Savona in northwestern Italy, he rose from modest origins through the Franciscan Order to become one of the most consequential — and controversial — figures in the history of the Catholic Church. He served as head of the Church and leader of the Papal States from August 9, 1471, until his death on August 12, 1484, at the age of seventy.
Francesco della Rovere's father was Leonardo Beltramo di Savona della Rovere, and his mother was Luchina Monteleoni. His decision to join the Franciscan Order as a young man seemed, on the surface, an unlikely path for someone who would eventually become one of the most politically engaged popes in Church history. Yet the order provided him with a rigorous intellectual environment. He studied philosophy and theology at the University of Pavia, revealing intellectual gifts that led him to lecture at Padua and numerous other Italian universities. In 1464, at the age of fifty, he was elected Minister General of the Franciscan Order. In 1467, Pope Paul II appointed him cardinal, assigning him the titular church of the Basilica of San Pietro in Vincoli.
Before becoming pope, Cardinal della Rovere had built a reputation not for worldly ambition but for scholarly piety. He had written learned theological treatises, including works titled On the Blood of Christ and On the Power of God. It was this reputation for genuine intellectual and spiritual devotion that inclined the College of Cardinals to elect him pope following the unexpected death of Paul II. Upon his election, he took the name Sixtus, a papal name that had not been used since the fifth century.
One of his first acts as pope was to call for a renewed crusade against the Ottoman Turks, targeting Smyrna. The fleet assembled for this purpose ultimately disbanded after Smyrna fell, and subsequent efforts to achieve union with the Greek Church yielded no meaningful results. Sixtus soon turned his energies from military and ecumenical ambitions toward temporal politics and the advancement of his family — a practice then broadly understood as nepotism and for which he became particularly notorious.
The frescoes by Melozzo da Forlì from Sixtus's pontificate reveal the scale of this family favoritism visually, showing the pope surrounded by members of the Della Rovere and Riario families. Among those elevated was his nephew Pietro Riario, who was successively made a cardinal, the bishop of Florence, the Patriarch of Constantinople, and given approximately 45 additional benefices. Pietro became one of the richest men in Rome and exercised substantial unofficial power, reportedly spending 200,000 gold ducats on food and festivities over just two years. He died prematurely in 1474, with contemporaries regarding his death as unnaturally early. Another nephew, Giuliano della Rovere, was also elevated and would go on to become Pope Julius II. Girolamo Riario and Giovanni della Rovere were among others who benefited from the pope's patronage. Contemporary chronicles, most notably the Diary of the City of Rome written by historian Stefano Infessura, leveled harsh personal accusations against Sixtus, describing alleged sexual misconduct, charges that circulated widely and inflamed perceptions of the pontificate.
Beyond the politics of nepotism and family advancement, Sixtus IV left enduring architectural and cultural monuments. His most celebrated legacy is the construction of the Sistine Chapel, which bears his name — Cappella Sistina derives directly from Sixtus. The chapel became the sacred space within the Vatican that subsequent popes and painters, including Michelangelo under Julius II, would transform into one of the greatest artistic achievements in Western history. Sixtus also established the Vatican Library in its modern institutional form, creating one of the most important repositories of classical and religious knowledge in the world.
As a patron of the arts, Sixtus was directly responsible for bringing to Rome the group of painters who ushered the early Renaissance into the city, initiating a new artistic age. He oversaw the creation of the first masterpieces of this Roman Renaissance transformation. He also issued the Papal bull Exigit Sinceræ Devotionis in 1478, formally creating the Spanish Inquisition — an institution that would operate in Spain for centuries with profound and often brutal consequences for religious minorities. He also annulled the Pontifical decrees of the Council of Constance, repositioning papal authority on several contested theological and ecclesial questions.
Sixtus IV also became personally embroiled in secular Italian politics in a way that crossed unmistakably ethical lines. He was personally involved in the Pazzi conspiracy of 1478, a plot orchestrated to assassinate Lorenzo and Giuliano de' Medici and remove the Medici family from power in Florence. The conspiracy succeeded in killing Giuliano but failed to eliminate Lorenzo, triggering a political and military crisis that embroiled the papacy in prolonged conflict with Florence.
Pope Sixtus IV died on August 12, 1484. His pontificate had been one of the most architecturally transformative in the history of Rome, leaving behind the Sistine Chapel and the Vatican Library as monuments that would outlast every controversy surrounding his name. The complexity of his legacy — genuine Renaissance patron and institutional builder on one hand, nepotist and political conspirator on the other — captures the contradictions of an era in which the papacy operated as both a spiritual and a thoroughly worldly power.
