During the fourteenth century, the family, belonging to one of the worker's guilds at Bologna, had gained power as pro-papist Guelph leaders in the fourteenth century. Amid the faction-conflicts of the commune, on 14 March 1401, Giovanni I Bentivoglio, with the help of Gian Galeazzo Visconti, declared himself " signore" and "Gonfaloniere di Giustizia". The Visconti however soured on Giovanni, and he was defeated and killed on 26 June 1402 at the Battle of Casalecchio and was interred in the church of San Giacomo Maggiore.