In order to secure the support of the other powerful families of Italy, Giovanni fought personally as condottiero. In 1467 he was at the service of Florence, Milan and Naples against Bartolomeo Colleoni, and in 1471 again for Milan, but his first military deeds occurred only in 1477 when he besieged Faenza for the Sforza. In 1482, during the War of Ferrara, he helped Ercole d'Este against Pope Sixtus IV and Venice. He later fought in small struggles for the Kingdom of Naples, but his personal interventions were always limited by the Bolognese institutions.