 It lost territories in 1013, to establish the Territorial Abbey of Sansepolcro, and on 19 June 1325 to establish the Diocese of Cortona.The first-known bishop of this see was Ennodius, present at a Roman council (465) under Pope Hilary.In 711 Arian Longobards put to death the bishop of the city, Albertus, and his deacon Britius.