For 10 points, name this island separated by the Strait of Messina from mainland Italy.
A conquest of this place by Ziyadat Allah I saw a sacking of Taormina, after which this place was controlled by the Aghlabid dynasty.  The Mamertine mercenaries were brought here by Agathocles, and the Peace of Caltabellotta ended a war fought over this place that involved Charles the Lame and Roger of Lauria.  That war began with a revolt led by John of Procida which fought against Charles of Anjou in favor of Peter III of Aragon.  In addition to that revolt named for evening prayers, its namesake "Vespers," this place was grouped with Naples in the Kingdom of Two of this city.  For 10 points, name this island separated by the Strait of Messina from mainland Italy.
A conquest of this place by Ziyadat Allah I saw a sacking of Taormina, after which this place was controlled by the Aghlabid dynasty.  
Sicily