Following the collapse of Roman and later Lombard authority in southern Italy, a group of semi-independent principalities evolved between the 8th and 11th centuries: * Principality of Benevento, a former Lombard duchy, independent from 774 * Principality of Salerno, split off from Benevento in 851 * Principality of Capua, split off from Benevento in 981 * Duchy of Naples, a former Byzantine province, a hereditary principality from 840 * Duchy of Gaeta, its ruler took the title Duke in 933 * Duchy of Amalfi, its ruler took the title Duke in 958 * Duchy of Sorrento, usually under the authority of Amalfi * Emirate of Bari, an Arab state, founded in 847, conquered in 871 * Emirate of Sicily, independent from 965 * County of Aversa, a Norman fief of Naples from 1030, conquered Capua