Porto Azzurro is a comune (municipality) in the Province of Livorno in the Italian region Tuscany; it is on the island of Elba, located about 130 kilometres (81 miles) southwest of Florence and about 90 kilometres (56 mi) south of Livorno. It was formerly called Porto Longone, and in 1557 Iacopo VI Appiani, Prince of Piombino, granted Spain the right to build a fortress there. It was transferred to the Kingdom of Naples in 1735 under the terms of the 1725 Treaty of Vienna, and then to France in 1801, when Napoleon established the Kingdom of Etruria.