f Muhammad his followers were the masters of an empire greater than Rome" (1). Yet even at its apogee, the Arab world was ridden with factional strife and schisms. These included the battle over the succession which ultimately led to the assassination in 661 of the Prophet's cousin and son-in-law Ali and the great split between Sunni and Shia Muslims (literally 'followers of Ali') and a great many other schismatic movements. Kennedy says the Arabs' quarrels were mainly over "who should be caliph and what powers was he to have and who should constitute the elite of the Islamic state" (87).
Fragmentation. The Arab Empire was further expanded and control over it consolidated under the Abbasid Caliphate (750-1258) in Baghdad. However, Hourani says that "by the tenth century the caliphate was breaking up, and rival caliphates appeared in Egypt [under the Fatimids 989-1171] . . . and in Spain" (5). Long before their Empire was finally destroyed when the Mongols sacked Baghdad in 1258, Lapidus says "the Abbasid regime was locked into constant struggle with its opponents" (80). He says its central authority was weakened by "a political, a social and an economic transformation" that "led to the substitution of small states for a unified regime" (136).
Ironically, as Arab unity disintegrated, Islamic culture and religion spread and placed deep roots throughout the Middle East, North Africa and other areas. According to Lapidus, at first Islam represented a somewhat superficial imposition by a small and greatly outnumbered military and religious elite in the conquered territories (xx). Notwithstanding the breakdown of Arab political unity, Hourani says "the cultural unity of Islam . . . grew deeper . . . and the faith of Islam articulated itself into systems of belief and institutions" (281). In the central portions of the Arab empire, succeeding barbarian tribes fell under the sway of Islam. They generally adopted the Islamic religion and...