Corsica and the Pope: finally, in 1450 Genoa ceded the administration of the island to its main bank, the Bank of Saint George, which brought peace. In the 16th century, the island entered into the fight between Spain and France for the supremacy in Italy. In 1553, a Franco-Ottoman fleet occupied Corsica, but the reaction of Spain and Genoa, led by Andrea Doria, reestablished the Genoese supremacy on the island, confirmed by the Peace of Cateau-Cambresis. The unlucky protagonist of this episode was Sampiero di Bastelica, who would later come to be considered a hero of the island. Their power reinstated,
Corsica was divided in "pagi", which in the Middle Ages became the "pievi", the basic administrative units of the island until 1768. During the diffusion of Christianity, which arrived quite early from Rome and the Tuscan harbors, Corsica was home to many martyrs and saints: among them, the most important are Saint Devota and Saint Julia, both patrons of the island. Corsica was integrated into Roman Italy by Emperor Diocletian (r. 284-305). In the 5th century, the western half of the Roman Empire collapsed, and the island was invaded by the Vandals and the Ostrogoths. Briefly recovered by the Byzantines, it