History of Corsica dislodge Paoli were futile, in 1764 by secret treaty Genoa sold Corsica to the Duc de Choiseul, then minister of the French Navy, who bought it on behalf of the crown. On the quiet, French troops gradually replaced Genoese in the citadels. In 1768, after preparations had been made, an open treaty with Genoa ceded Corsica to France in perpetuity with no possibility of retraction and the Duc appointed a Corsican supporter, Buttafuoco, as administrator. The island rose in revolt. Paoli fought a guerrilla war against fresh French troops under their commander, Comte de Marbeuf, but was defeated in the
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