Duchy of Naples

The Duchy of Naples was the Greek duchy of the Tyrrhenian coast, a Byzantine province constituted in the seventh century from the Campanian lands the Lombards had failed to conquer. Ruled by a military dux, it won the right to a local duke in 661 when Constans II granted Naples to Basil, and in 840 Sergius I made the succession hereditary, sealing de facto independence for a state that endured more than five centuries. Its harbors held Vesuvius, the Sorrentine peninsula, Capri, Ischia and Procida, the Phlegraean fields and the Nola country, while its sister duchies Gaeta, Amalfi and Sorrento broke away in the early ninth century. The dukes balanced Lombards, Franks, Arabs and Byzantines with the suppleness of a port city, until the Norman tide closed in: in 1137 Sergius VII surrendered to Roger II of Sicily, and the last Greek duchy of the mainland entered the Norman kingdom.