Complex sentence: Corrado, however, decided to break with the Papal authority: assailed by Cardinal Giovanni Maria Vitelleschi, he lost Foligno, which therefater lost its autonomy and became part of the Papal States.
Split into simpler sentences: Corrado, however, decided to break with the Papal authority. Assailed by Cardinal Giovanni Maria Vitelleschi, he lost Foligno, which therefater lost its autonomy and became part of the Papal States.