However, Piccinino's family actually owned a house with a nearby butchery, and were part of the landed middle class, and, according to tradition, one of his uncles had been podestà of Milan.

After serving for a short period under the Florentine Republic, he went over to Filippo Maria Visconti, duke of Milan (1425), in whose service together with Niccolò Fortebraccio he fought in the Wars in Lombardy against the league of Pope Eugene IV, Venice and Florence.

He was defeated by Sforza at the Battle of Anghiari (1440), but although a number of his men were taken prisoner, they were liberated at once, as was usually done in wars waged by soldiers of fortune.

[2] The duke by way of reply concluded a truce with Sforza; but the latter, who, while professing to defend the Papal States, had established his own power in the Marche, aroused the fears of the pope and the king of Naples, as well as of the Visconti, who gave the command of their joint forces to Piccinino.

[2] Short of stature, lame and in weak health, he was brave to the point of foolhardiness, resourceful, and rarely overwhelmed by defeat.