Islam: Expansion to 750

The trajectory of the military expansion of Islam is not dissimilar to the Mongol conquests of Timur or Genghis Khan. The initial phase was painstaking, with many reverses, before the unification of the warring tribes of Arabia in a religious polity, which was followed by an explosive advance, in all directions. Within a decade of Muhammad’s death, the Sassanid Empire had been vanquished at Nehavend (642) and the Byzantines expelled from Syria after Yarmuk (636) and Egypt, after Heliopolis (640). A century later, Islamic armies vanquished the Chinese Tang, at Talas (751) in Transoxiana, and were eventually halted by the Franks in Aquitaine. The most intractable enemies proved to be fellow Muslims: two Fitnas (civil wars) pitted Shiite against Sunni (656–61; 680–92) and the Berber revolt in North Africa, Zaydi revolt in Kufa, and Harith revolt in Khurasan were all Islamic, and religious in