This significant new work focuses on the formation and disintegration of Arab-Muslim rule and society in Sicily and south Italy between 800 and 1300 which led to the creation of an enduring Muslim-Christian frontier during the age of the Crusades. It examines the long and short-term impact of Islamic authority and culture on these regions and how they later fell into the hands of European rulers, explaining how the Norman conquest of Sicily came to import radically different dynamics to the central Mediterranean. The change of ruling elites left a majority Muslim population under Christian rule, but the Sicilian kings also adopted and adapted political ideologies from south Mediterranean regimes while absorbing cultural influences from the diverse peoples over whom they ruled. This work provides an engaging, expert and wide-ranging introduction to the subject and offers fresh and clear insights into the politico-religious, socio-economic and cultural evolution of Europe and the Islamic world.