The island of Sicily was originally under the Hohenstaufen. But in 1266, Charles of Anjou came to power in Naples-Sicily after defeating and killing regent Manfred. In 1268 Konradin, the last descendant of Friedrich II, was killed by him. This had consequences: 1282, the Sicilian vespers broke out, and all French on the island were killed. Sicily became part of Aragon. In 1285, the French started the Aragonese Crusade as a revenge for Sicilian vespers, but with no success.
In the year 1414 for the first time for centuries, people in Western Europe were horrified again of "Asian hordes": A Seljuk-Barbary fleet crossed the Adria, lands near Taranto / Otranto, swept through Apulia. The king of Naples was horrified and asked anyone he could contact for help. Without success: France was still locked in a hard war with England and Castille; the Hungarian king would have actually liked to help, but the powerful nobles forbad him to send an army south while Hungary proper was threatened; the northern Italian states were busy mopping up the smaller states in the region. The pope called for a crusade, but even that didn't help much. Being desperate, the king made an alliance with Naples' old enemy Aragon, ceding Sicily officially, for once and ever, to them. The new alliance managed to defeat the Rum-Seljuks in the South. Especially their cannons helped them a lot to reconquer the cities. Only Taranto and Bari in Apulia were held by the Seljuks. In 1418, an armistice was made - but both sides planned to restart war, when the time was right. Naples was conquered in the Great Napolitan War, and Aragon-Sicily watched; but later, they would have to suffer themselves. 1453, Aragon actually provoked the Seljuks by landing troops in Calabria, winning some battles in the beginning. When the main army of the Seljuks arrives, they were beaten back to Sicily, however. In 1455, the Seljuks landed on Sicily, conquering it completely in 1456.
Under Seljuk rule
As in the other occupied Italian areas, the Carbonari were very active in Sicily. In the cities however, Muslims settled, developed the trade with the rest of the empire, and brought many new influences.
When the Triple Monarchy of England-Castille-Portugal fell apart, in 1629 the disgraced commander of the Mediterranean fleet, a duke Francisco of Álvarez, went to Sicily, together with the occupation forces fled from the Marches and Algeria, to set up the (unrecognized) kingdom of Sicily (incl. Tunis, Malta and the Baleares). Threatened by the Seljuks, he made an alliance with France. 1634, even Spain acknowledged the independence of Sicily (not however, the fact that Sicily was a kingdom), got the Baleares back. 1639, Sicily conquered Sardinia and Corsica with their fleet. Princess Mary of Spain had a plan to marry her sister Isabella to king Francisco, but failed.
During 1660-67, Florence and Venice waged war against Seljuks, despite that France didn't fight with them, and were promptly defeated. The humbled Florence even needed Sicilian help to evacuate their troops from Greece. For this help, Florence made a dynastical marriage with Sicily, between king Francisco II and the only surviving child of grand duke Lorenzo III, Condolcessa. (Even besides the political consequences, the marriage is considered a scandal - there were rumors that Condolcessa was the mistress of both her father and her uncle, late grand duke Giovanni III.)
Part of Italy
During the war, when the Medici dynasty died out in 1688, Sicily and Florence united, to form the Italian kingdom.
1693, an Earthquake happened on Sicily. The old royal palace was also destroyed, helping king Francisco / Francesco I to move the court to Rome.