The dynamic expansion of the Muslim world following the death of Mohammed exposed Sicily first to Saracen raids and then to invasion. The first invasion, by Saracens from North Africa beginning in 827, bogged down after initial success at Agrigento and along its neighboring coast.

Then in 831 a much stronger Saracen force arrived from Europe itself, where Saracens had earlier overrun the Iberian peninsula. The Iberian invaders seized Palermo [Panormus] in 831, but further gains came slowly against determined resistance by Sicilians and by the imperial forces of the Byzantine [Eastern Roman] Empire on the island. Messina fell in 843 and Enna in 859, while Syracuse and Taormina repelled successive attacks. Finally, however, mighty Syracuse itself was captured in 877.

In a period of 50 years the Saracens had captured all of Sicily except a few scattered strongholds along the eastern coast, such as Taormina and Rametta. Surprisingly, the final and complete conquest of Sicily by the Saracens was still almost 90 years away, delayed by internal warfare among the Saracens and by fierce Sicilian defense.