Born to a poor family in Genoa in 1414, Francesco della Rovere joined the Franciscans at a young age and studied philosophy and theology at the University of Pavia. It turned out that young Francesco was no intellectual slouch, so he soon began lecturing at multiple universities across Italy. At the age of 50, Francesco was named Minister General of the Franciscan order, and three years later Pope Paul II made him a cardinal to boot. He was widely known as a pious man with a solid moral constitution, having written documents on the Precious Blood, the Immaculate Conception, and the power of God.

The next successor of Peter, chosen in a conclave that convened on August 7, 1471, styled himself “Sixtus IV” after St. Sixtus II, the pope and martyr whose feast day was being celebrated. Pope Sixtus IV’s first order of business was leading a crusade against the Turks in Smyrna, which proved successful, and was paid for in large part by the myriad treasures Pope Paul II had hoarded during his reign. Sixtus then tried to reconcile with the Greek and Russian Orthodox churches, to no avail.

The pope’s lone vice was a nepotism that saw him heaping benefits on several unworthy relatives -- decisions which would harm the Church for decades. One unfortunate instance saw his nephew, Cardinal Rafael Riario, trying to boot the Medicis out of power in Florence, and not through nonviolent means. The plot, which wasn’t endorsed by Sixtus, led to all sorts of unrest that may even have quickened the pope’s death due to stress. In office for 13 years and three days, Sixtus IV died August 12, 1484 and is buried in St. Peter’s Basilica.  

Without a doubt, Pope Sixtus IV’s greatest contributions to the Church and the world were the construction of the Sistine Chapel (which is named after him), officially giving a home to Nicholas V’s Vatican Library, and gathering the group of artists who ushered in the early Renaissance. Leonardo da Vinci in particular gained his first notoriety during the reign of Sixtus IV. During this papacy, da Vinci completed landmark works like the Baptism of Christ and the first edition of his Virgin of the Rocks, which depicts the infant John the Baptist, Mary, and an angel all worshiping the infant Jesus.

Sixtus IV also canonized the great St. Bonaventure in 1482:

Fun Fact: At some point during his papacy, Sixtus issued a papal bull that allowed the bodies of executed criminals and unidentified persons to be used by doctors and artists for dissection. This access led to several advances in the study and knowledge of human anatomy, one fruit of which was the famous work De humani corporis fabrica (“On the fabric of the human body”), published by Vesalius in 1543.

The oldest university in Sweden and all of Scandinavia, Uppsala University, was founded in 1477, and is still in operation today.