 Complete the following phrase:  Under Muslim rule, the island became increasingly prosperous and cosmopolitan. Trade and agriculture flourished, and Palermo became one of the largest and wealthiest cities in Europe. Sicily became multiconfessional and multilingual, developing a distinct Arab-Byzantine culture that combined elements of its Islamic Arab and Berber migrants with those of the local Greek and Latin Christians, and Jewish communities. Beginning in the early eleventh century, the Emirate began to fracture from internal strife and dynastic disputes. Christian Norman mercenaries under Roger I ultimately 