Ceiling fresco with the Medici coat of arms

The vault was painted in 1643 and 1644, while Tuscany was at war. Ferdinando II had joined Venice and Modena against Pope Urban VIII over the duchy of Castro, and in September 1643 his brother Mattias beat a papal army at Mongiovino. Overhead, fighting runs right around the edge of the ceiling, Hercules builds a trophy out of captured weapons handed to him by the twin horsemen Castor and Pollux, and a line of prisoners walks toward figures of Victory, Abundance and Peace. The programme is the schooling of a young prince in war, with Mars as his instructor. At the very centre a crowd of putti carries the Medici arms upward, and the crown above them has Ferdinando's own name written inside it.