 Later he fought the Venetian cardinal Pietro Barbo, who was to become Pope Paul II; in honourable defeat he was sent to Romania to lead the Pope's troops.Family contentions were calmed by the marriage in 1480 of Gentile's son, Pietro Antonio Monaldeschi della Vipera della Sala with his cousin Giovanna Monaldeschi della Cervara.The Monaldeschi della Cervara had invested themselves with Bolsena, where they built the fortifications that are still a prominent feature.