Shortly after Federico Gonzaga took over the office of captain general of the Milanese troops in 1478 from his father Ludovico, papal troops besieged the town of Legnano that was on Milanese territory. However, when Federico marched towards them, they withdrew without a fight. This dramatic battle scene is, therefore, purely fictional. Originally the equestrian figure in the middle of the picture was the field commander. At the client’s request, Tintoretto later added the protagonist’s physiognomy to the belligerent mounted figure in the foreground.