The decade between 715 and 724 was a turning point both in the character of the Umayyads’ empire and the fortunes of the dynasty itself. More than three generations away from the time of the Prophet, and two generations from the end of the first wave of conquests, the social structures within the empire were changing fast. These changes are reflected in language, with ‘Muslims’ (muslimūn) increasingly used alongside the ‘Faithful’ (mu’minūn), and with ‘Migrants’ (muhājirūn) disappearing from use. ‘The Arabs’ (Ar. al-‘arab) begins to appear more often in the poetry and in the documentary evidence with a collective sense. At the same time, the incorporation of perhaps tens of thousands of enslaved women into the Muslim population, alongside male non-Arabian captives and migrants, was transforming the character of group identities within the garrisons. From this period and after, anxieties about non-Muslims ruling over Muslims and conflicts about unequal treatment of recent converts become prominent features of the source material, as do pressures on tax revenue. These social and economic tensions coincided with an era of dynastic instability, with four caliphs dying in quick succession within the decade. As the caliphs’ supporters jockeyed for power and influence, a major rebellion broke out in Iraq for the first time in a generation and new kinds of unrest appeared in North Africa and Khurasan. Moreover, these short caliphates came after the disastrous failure in 718 of the Marwanids’ aspirations to conquer the Roman Empire and replace the Romans as the representatives of true monotheist faith. Defeat at the walls of Constantinople shook the ideological foundations which had been established by ‘Abd al-Malik and his son al-Walid.

Sulayman b. ‘Abd al-Malik and the Siege of Constantinople

The new caliph, Sulayman b. ‘Abd al-Malik, installed his Muhallabid allies in Iraq and the eastern frontier provinces of Sind, Sistan and Khurasan. Reprisals against their enemies continued; the former governor of Sind, Muhammad b. al-Qasim, and a number of other relatives of al-Hajjaj are said to have been tortured and killed at Wasit. New frontier warfare also began; Yazid b. al-Muhallab, who was made governor in Iraq and Khurasan, set out with thousands of soldiers from Syria, Iraq and Jibal for Jurjan and Tabaristan, east and south of the Caspian (modern northern Iran).