Mainland southern Italy and Sicily were conquered independently by various Norman knights, the former from the Byzantines and Lombards, the latter from the Saracens, in the course of the eleventh and early twelfth centuries.
They were formed into the Kingdom of Sicily, with its capital at Palermo, under Count Roger II of Sicily (1130).
This kingdom was conquered successively by the Hohenstaufens (Swabia) and the Angevins (Anjou and Provence ); Charles I of Anjou moved the capital to Naples.
Under the Angevins, and thereafter, the mainland is known as ‘Sicilia citra Farum’ (i.e., Sicily on this side of the lighthouse marking the straits of Messina), but comes often to be called the Kingdom of Naples; the island of Sicily is known as ‘Sicilia ultra Farum’ (beyond the lighthouse).
The revolt known as the Sicilian Vespers (1282) separated the island from the mainland and placed it under Aragonese rule; after the conquest of Naples by Alfonso of Aragon (1435-42) the island and the mainland came again under a single ruler, but on Alfonso’s death (1458) they were again separated; the conquest of Naples by Ferdinand of Aragon (1501-04) once more placed them under a single ruler, but administrative union in the form of the ‘Kingdom of the Two Sicilies’ was not carried through until 1816.