Despite his integral role in the administration, Salih did not hold an official post under al-Hajjaj; the caliphs Abd al-Malik (r. 685–705) and al-Walid I (r. 705–715) combined the military and fiscal responsibilities of Iraq and the east into the singular authority of al-Hajjaj.[7] Salih was referred to as the ṣāḥib dawāwīn, akin to the superintendent of Iraq's central tax bureaux in Wasit.[8] When, in 702, al-Hajjaj built Wasit as the new capital of Iraq and the garrison of his elite Syrian troops, the costs of construction totaled 43,000,000 dirhams, a sum far more expensive than the governor had anticipated. To rectify the budget, Salih attributed about 80% of the cost to war expenses, and the remainder to construction.[9]