 However, after the rise of Pope Pius II, he had to fight constantly for the independence of the city.In 1463 he was forced to submit to Pius II, who left him only Rimini and little more; Roberto Malatesta, his son (1482), under Pope Paul II, nearly lost his state, but under Pope Sixtus IV, became the commanding officer of the pontifical army against Ferdinand of Naples.Sigismondo was, however, defeated by Neapolitan forces in the battle of Campomorto (1482).