The previous attribution of this funeral monument design to Michelangelo (1475-1564), given by the old inscription on its verso, shows the influence that Michelangelo's works had on the author of this sheet. In particular the two statues lying on the entablature above the chapel are reminiscent of Michelangelo's tombs in the Medici Chapel.
Relationships between Michelangelo and Sangallo had not been good. When Paul III became Pope in 1536, he appointed Antonio as papal architect; for him Antonio continued the papal apartments in Castel Sant'Angelo, and worked to restore and strengthen the entire defensive system for the walls of Rome. Some of his projects never saw completion because of disagreements with Michelangelo who had become the Pope's military consultant in 1545.