Palazzo Vecchio 2025: Florence's Fortress-Palace and Its Secret Rooms

Why Leonardo's Battle of Anghiari might still be in the walls — and why we may never know

The Battle of Anghiari commission (1503-1504) would have been Leonardo's largest painted work — a massive wall fresco of the 1440 Florentine victory over Milan, to cover the Salone dei Cinquecento's eastern wall. Leonardo began the cartoon (the full-scale preparatory drawing) and started painting, but his experimental technique (applying a wax-based medium over the plaster rather than standard buon fresco) failed when the paint began to run in cold temperatures. He abandoned the project in 1506 when called to Milan by the French governor. When Vasari was commissioned to repaint the Salone walls in 1563, the question of whether he plastered over Leonardo's partially complete work or demolished it entirely has never been resolved. A 2012 project by Maurizio Seracini using non-destructive reflectography found an air gap and trace of black pigment behind the Vasari surface in the specific section where historical accounts place the Leonardo work — suggesting a layer preserved behind rather than demolished. Extractive testing would require damaging the Vasari frescoes (themselves important works), creating the specific dilemma: destroying certain Vasari to potentially recover uncertain Leonardo.