How did the Great Schism weaken the Papal States?

The Great Schism (1378–1417) severely weakened the Papal States, leading to their virtual dissolution. During this period, the existence of rival popes in Rome and Avignon—and eventually a third pope elected at the Council of Pisa—undermined previous efforts to consolidate papal authority.12

As central control collapsed, the papacy lost its ability to command obedience from its vassals. Consequently, large regions including southern Emilia, the Romagna, the Marche, and Umbria were effectively ceded to local signori who acted as "papal vicars". In cities like Bologna and Perugia, powerful local families established their own predominance, while in Lazio and Rome itself, the church faced persistent threats from baronial families and lingering republican sentiment. This left the papacy in a precarious position, struggling to assert temporal authority until the restoration of unity under Martin V.213