In the same year Nasr renewed his attempt to subject Shāsh to the Moslem yoke. The campaign was a bloodless one. He received the submission of Ushrūsana, and concluded an advantageous peace with the king of Shāsh.[165] He thereupon appointed a Mohammedan governor of Farghāna.
In the year A.H. 123 (740) this judicious ruler established order throughout Transoxiana, Khorāsān, and Farghāna.[166] But he had other difficulties to meet which were not of his own making. The star of the Umayyads was in the descendent, and the `Abbāsid party were daily adding to the number of their adherents. And, apart from dynastic struggles, the whole of Islām was rent with the dissensions of the rival sects of the Khārijites and the Shi`ites. The sectarian zeal of the latter, which to this day remains the cause of bitter discord in the realm of Islām, began now to make itself felt in Persia and in Central Asia.
In A.H. 125 (742) Hishām, the last Umayyad Caliph of any distinction, died. The dynasty lasted seven years longer, and in that short period no less than four Caliphs[167] attempted to restore the fading glory of their house. While such disorders reigned at headquarters there was small hope of quelling sedition in the outlying provinces. The `Abbāsid pretender, Ibrāhīm, thanks to the efforts of his father’s[168] emissaries, had now a powerful and rapidly increasing faction in Merv. But Nasr still held command in Khorāsān, and his personal influence was still great enough to avert open rebellion. It failed; and the fierce tribal jealousy which always smouldered in Arab breasts burst into civil war. The two rival factions were the Yemenites and the Modharites. Nasr ibn Sayyār belonged to the tribe of Modhar, and bestowed the highest offices on his clansmen. In fact, all the towns of Khorāsān were governed by members of one or the other of the three principal branches of the tribe, Asad, Temīm, or Kināna. Now, there was a man of the tribe of Azd called, after his birthplace, Juday` El-Kirmānī, who, before the promotion of Nasr, had held a higher position, and retained some authority among his own people. To him came the Beni Rabī`a with complaints of the partiality of Nasr. He promised his intercession with the governor. On attempting remonstrance he raised Nasr’s ire, and was cast into prison, whence escaping[169] he rejoined his own people. All efforts at reconciliation proving fruitless, the rival parties had recourse to armed strength. In A.H. 127 (744) Hārith ibn Surayj, who was permitted to return to Khorāsān from his captivity in Fārāb, set up his standard at Merv, and, gathering many followers around it, openly revolted against Nasr. In the following year Nasr called upon him to swear allegiance to the Caliph Merwān, but Hārith refused, and boasted that he was “the man with the black flag”[170] who was to overthrow the Umayyad dynasty. Hostilities thereupon commenced between Nasr and Hārith, in which the latter was worsted. He fled to the camp of El-Kirmānī, whom Nasr had meanwhile been vainly endeavouring to conciliate.