The subject which he chose to treat was the battle of Anghiari in 1440, when the Florentine mercenaries entirely routed the troops of Filippo Maria Visconti, led by Niccolo Piccinino, one of the greatest generals of his age.

In August 1504 Soderini commissioned Michelangelo to prepare Cartoons for the opposite wall of the great Sala, and assigned to him a workshop in the Hospital of the Dyers at S.Onofrio.A minute of expenditure, under date October 31, 1504, shows that the paper for the Cartoon had been already provided; and Michelangelo continued to work upon it until his call to Rome at the beginning of 1505.

Lionardo's battle-piece consisted of two groups on horseback engaged in a fierce struggle for a standard.

Michelangelo determined to select a subject which should enable him to display all his power as the supreme draughtsman of the nude.

He chose an episode from the war with Pisa, when, on the 28th of July 1364, a band of 400 Florentine soldiers were surprised bathing by Sir John Hawkwood and his English riders.