despite the turmoil that swept the Caliphate after 743. When Yazid III came to power in early 744, he initially ordered Nasr replaced. Nasr refused to accept this, and held on to the post, being eventually confirmed to it a few months later. After Marwan II's rise to power in December 744, he likewise affirmed Nasr's position. Reforms and campaigns Nasr gave his province an unprecedented period of good government, stability and prosperity, so that, in the words of the 9th-century historian al-Mada'ini, "Khurasan was built up as it had never been before". His major achievements during his tenure were the reform of the tax system and the restoration of Umayyad control over Transoxiana. The Khurasani tax system had been established at the time of the Muslim conquest and remained unchanged since. It relied on the collection of a fixed tribute by the local non-Muslim (mostly Zoroastrian) gentry, the s, who often discriminated against the Muslim settlers and the native converts. This contributed to the latter's increasing resentment of Umayyad rule, and the demand for a tax reform had fuelled past revolts like that of Ibn Surayj. Consequently, Nasr streamlined the tax system in 739, implementing a blanket imposition (the ) on all owners of agricultural land and forcing the non-Muslims to pay an additional poll tax (the ). In this way, the chroniclers report, 30,000 Muslims were absolved of the , and 80,000 non-Muslims were forced to pay it instead. Attention was also paid to the accurate collection of the in accordance with treaties with the local rulers, as a result of which the tax burden was generally eased. This reform is traditionally held to have assisted in regaining the loyalty of the local populations and their princes, who returned quickly to the Arab fold. Other modern scholars however consider the effect of this belated reform on the prevailing anti-Umayyad climate as minimal. Upon his appointment, Nasr also moved the provincial capital back to Merv from Balkh, where Asad had established it. Additionally, for the first time in the province's history he appointed sub-governors. They were drawn from among his allies and supporters in order to reward them and to improve his own control of the province. Taking advantage of the disintegration of the Türgesh khaganate after the murder of the Suluk, Nasr moved aggressively across the Oxus. His first campaign, immediately after his appointment, was in the area