Sicily has been a grain-producing island since the Greco-Roman period, and this situation lasted until the Byzantine Empire. By the 8th century, the Arabs had swiftly conquered large territory, and Sicily was also occupied by Muslims in the wave. The Islamic regimes brought advanced civilization to the region. Under constant Islamization, Sicily, like Andalusia, became one of the developed regions of high civilization in Europe at that time.
In the early 11th century, Sicily suffered from wars and the island was vanquished by the Normans; then, the political power of Sicily returned to the Christians. However, the Islamization of Sicily still continued under the reigns of early Norman monarchs until the Pope provoked to recover the holy city Jerusalem and launched the Crusade. Under such zeitgeist, the dilemma of Muslims grew more critical gradually, even after the Holy Roman Empire entered Sicily.
Frederick II, the emperor of Holy Roman Empire, was willing to accept the civilization of Islam. Under his rule, the last glory of Sicily bloomed. However, the relations between the Christians and Muslims turned into its dark period. In this very situation, Muslims in Sicily were either forced to move into Italy or convert to Christianity, and finally, they vanished under the House of Anjou.