Sixtus IV Appoints Bartolomeo Platina Prefect of the Vatican Library

Every man standing in this room is a relative of the pope. Sixtus IV, enthroned on the right, had raised his nephews to high office, and Melozzo painted them around him around 1477. The tall young cardinal in red, standing in front of the throne, is Giuliano della Rovere, who 26 years later became Pope Julius II. Behind the kneeling figure stand Girolamo Riario and Giovanni della Rovere, and the group is completed by Raffaele Riario, then a young official of the papal court.

The man on his knees is Bartolomeo Sacchi, called Platina, a humanist who under the previous pope, Paul II, had been locked up in Castel Sant'Angelo. Now he was taking charge of the papal library, and he points at the Latin verses below, which he wrote himself. They list what Sixtus had rebuilt in Rome, churches, a home for foundlings, streets, squares, walls, bridges and the aqueduct that feeds the Trevi, and then say the city owes him still more for the library, brought out of squalor into a place of renown.

A year later two of these men were caught up in something else. In April 1478 Girolamo Riario was among the backers of the Pazzi conspiracy in Florence, and Raffaele Riario, already a cardinal though not yet 17, was in the cathedral there when Giuliano de' Medici was stabbed to death during Mass.