The Dukes of Naples were the military commanders of the ducatus Neapolitanus, a Byzantine outpost in Italy, one of the few remaining after the conquest of the Lombards. In 661, Emperor Constans II, highly interested in south Italian affairs (he moved his capital to Syracuse), appointed a Neapolitan named Basil dux or magister militum. Thereafter a line of dukes, often largely independent and dynastic from the mid-ninth century, ruled until the coming of the Normans, a new menace they could not weather. The thirty-ninth and last duke, Sergius VII, surrendered his city to King Roger II of Sicily in 1137.
c. 600 Gudeliscus, as duke of Campania (dux Campaniae)c. 603 Guduin, first recorded duke of Naplesc. 616 seized by the rebel John of Conzac. 625–38 Anatolius661–666 Basil666–670 Theophylactus I670–673 Cosmas673–677 Andrew I677–684 Caesarius I684–687 Stephen I687–696 Bonellus696–706 Theodosius706–711 Caesarius II711–719 John I719–729 Theodore I729–739 George739–755 Gregory I755–766 Stephen II767–794 Gregory II794–801 Theophylactus II801–c. 818 Anthimusc. 818–821 Theoctistus821 Theodore II821–832 Stephen III832–834 Bonus834 Leo834–840 Andrew II840 ContardusThese dukes were more independent than their predecessors and they were not chosen by the emperor, but the descendants of Sergius I, who was elected by the citizens.
840–864/865 Sergius I864/865–870 Gregory III870–877/878 Sergius II877/878–898 Athanasius898–c. 915 Gregory IVc. 915–919 John II919–928 Marinus I928–968/969 John III968/969–992/997 Marinus II992–997/999 Sergius III997/999–1005 John IV1005–1038 Sergius IV, co-ruling with his son (below) after 10331027–1029 under control of Pandulf IV of Capua1033–1050 John V, co-ruling with his father (above) before 1038 and with his son (below) after1038–1076 Sergius V, co-ruling with his father (above) until 10501077–1107 Sergius VI, co-ruling with his son (below) after 10901090–1122 John VI, co-ruling with his father (above) until 11071122–1137 Sergius VII1137–1139 vacantIn 1139, Naples capitulated to the Normans and shortly after elected a Norman ruler from the ruling dynasty.
1139–1144 Alfonso1144–1154 WilliamIn 1154, William succeeded to the Sicilian crown and the line of dukes ends.
