The monarchs of Sicily ruled from the establishment of the Kingdom of Sicily in 1130 until the "perfect fusion" in the Kingdom of the Two Sicilies in 1816.
The origins of the Sicilian monarchy lie in the Norman conquest of southern Italy which occurred between the 11th and 12th century. Sicily, which was ruled as an Islamic emirate for at least two centuries, was invaded in 1071 by Norman House of Hauteville, who conquered Palermo and established a feudal county named the County of Sicily. The House of Hauteville completed their conquest of Sicily in 1091.
In 1130, the County of Sicily and the County of Apulia, ruled by different branches of the House of Hauteville, merged as the Kingdom of Sicily, and Count Roger II was crowned king by Antipope Anacletus II. In 1282, after the Sicilian Vespers, the kingdom split into separate states: the properly named "Ultra Sicily" (Siciliae ultra Pharum, Latin for "Sicily over the Strait") and "Hither Sicily" (Siciliae citra, commonly called "the Kingdom of Naples").[1] Definitive unification occurred in 1816, when Ferdinand IV and III made the two entities into a single state, the Kingdom of the Two Sicilies.[2][3]