 Power thereafter derived from the Syrian troops, who became Iraq's ruling class, while Iraq's Arab nobility, religious scholars and "mawālī" were their virtual subjects.Furthermore, the surplus taxes from the agriculturally rich Sawad lands were redirected from the "muqātila" to Abd al-Malik's treasury in Damascus to pay the Syrian troops in the province.This reflected a wider campaign by the caliph to institute greater control over the Caliphate.