ABSTRACT
The relative power of the various peoples shifted gradually during the High Caliphate. The early Umayyads had inherited Roman bureaucratic traditions, but now Persian administrators took over and introduced Sassanid practices. Eventually, they reached China's northwest border, which became the eastern limit of the Arab conquests. Under Abd al-Malik's successor, a Muslim force crossed the Strait of Gibraltar and took most of present-day Spain and Portugal. It was not until 732—exactly a century after the Prophet's death—that a European Christian army stemmed the Muslim tide in northern France. A dark curtain had shrouded Persia's history after the Arab conquests destroyed the Sassanid Empire. Despite the fiscal reforms of Umar II and Hisham, the Umayyad caliphate remained an Arab kingdom. Then they went on to kill all the living Umayyads and to scourge the corpses of the dead ones. The Umayyads' weakness was the Abbasids' opportunity.
