In A.H. 116 (734) Junayd, in spite of his great services, was dismissed from his post by the Caliph for having married the daughter of Yezīd ibn Muhallab, and `Āsim ibn `Abdullah was appointed in his stead. He died of dropsy before his successor reached Merv. By his cruelty and injustice to all who had held office under Junayd, `Āsim incurred the bitter hatred of his people.
A certain Hārith ibn Surayj rose against him, took possession of many towns in Khorāsān, such as Merv er-Rūd, Balkh, and Bab-el-Abwāb, and gathered a crowd of soldiers of fortune to his banner by distributing amongst them the tribute levied from his acquisitions. `Āsim, failing to crush this revolt, was dismissed by the Caliph, and Asad el-Kasrī was reinstated in the governorship of Khorāsān.[160] Asad at once advanced against Hārith at the head of a large army, drove him to Turkestān, where he entered into league with the Khākān, who assigned him and his followers the town of Fārāb as a residence.
In A.H. 118 (736) Balkh became temporarily the Mohammedan capital of Central Asia. In the same year Asad planned a campaign into Khottal, but the Khākān took measures to forestall him. Asad’s advance column was taken completely by surprise, and his camp and harem were captured. A parley ensued without result, after which he returned to Balkh, while the Khākān again withdrew to Tokhāristān. But in the following spring Asad attacked and completely routed the Khākān and rescued all the Moslem provinces.[161] The Turk fled back to Tokhāristān, and shortly afterwards, while on his way to attack Samarkand, he was waylaid and killed by a rebellious follower.
In A.H. 120 (737)[162] Asad died, and was succeeded by Nasr ibn Sayyār, one of the ablest rulers and generals ever sent to the East in Mohammedan times. He was as generous as he was strong, and seems to have won the affection of those under him. During the nine years of his governorship his position was by no means an easy one, for he had to contend with the growing influence of the `Abbāsid faction,[163] and to support, with a loyalty worthy of a better cause, the last degenerate representatives of the house of Umayya. His first care on assuming the supreme command was to subjugate the Khākān of the Turks, whose name was Kūrsūl, against whom he led three successive expeditions. The first two seem to have been without result, but in the last, which was directed against Shāsh, the Khākān fell into his hands and was put to death.[164]