In 1440, he participated in the Battle of Anghiari and was badly defeated. On 19 August 1444 he was again defeated by Sforza's forces at Montolmo (now Corridonia) and taken prisoner, while his brother Jacopo was able to escape.
On 28 September the same year Piccinino suffered a defeat at Casalmaggiore. It was followed by a more serious one at Monte Brianza in 1447.
Despite these setbacks, he managed to gain a contract under the newly formed and short-lived Ambrosian Republic (1447-1450) together with Jacopo, in order to thwart Sforza's claim to be Duke of Milan. He did not live to see Sforza's victory. He fell ill and died in 1449. His symptoms included edema, which suggests several possible conditions or diseases that might have caused his death. He married Camilla da Montone,[1] daughter of the condottiero Braccio da Montone (1368-1424), in 1443.