Non-Arab Muslims. After the Muslim conquest of non-Arab lands in the eighth century, non-Arabs in these regions gradually but steadily converted to Islam, creating a demographic transformation of Muslim society. Arabs were no longer the only Muslims. Modern scholars explain the conversion of non-Arabs in many ways, the most common being economic. Non-Muslims paid two kinds of taxes; jizya and kharaj, both of which were higher than a Muslim's zakat and the 'ushr taxes. The jizya was paid by the People of the Book in lieu of military service and for protection by the state (thus, the designation "Protected People"). Theoretically, if one converted to Islam, such a tax no longer applied. There are several flaws in this widespread theory. First, the number of people who converted to Islam was much greater than those who achieved economic advantage...