A.H. 152 (769). Humayd ibn Kahtaba was appointed governor of Khorāsān, and proclaimed a Holy War against Kābul.
A.H. 158 (774). El-Mansūr died, and was succeeded by his son El-Mahdi.
A.H. 159 (775). Humayd was succeeded in the governorship of Khorāsān by Abu `Aun. A rising took place in Khorāsān in connection with the appointment of the heir-presumptive (_vali-`ahd_).
A.H. 160 (776). Another rising occurred in Khorāsān under the leadership of Yūsuf ibn Ibrāhīm, called El-Barm, which was quelled by Yezīd ibn Mazyad. Yūsuf was sent captive to El-Mahdi, who, after subjecting him to the cruellest torture, crucified him.
Abu `Aun having provoked the Caliph’s wrath was dismissed from his office, and succeeded by Mu`āz ibn Muslim.
A.H. 161 (777). The revolt of Mokanna`, “the Veiled Prophet of Khorāsān,” originated in a village near Merv. He taught the transmigration of souls, and gave out that the Deity had lately been incarnate in the person of Abū Muslim, and had now passed into his own. He secured a great following from among the people of Khorāsān and Transoxiana, who, from the colour of their clothes, took the name of _Sefīd-Jāmegān_, or the “White-robed.”
A.H. 163 (779). Mokanna` was besieged by Sayyid el-Harashī in his fortress in Kesh, and on finding his position hopeless poisoned himself. His head was sent to El-Mahdi in Aleppo.[198]
Mu`āz was supplanted by Musayyah ibn Zobayr in the governorship.
A.H. 166 (782). A general rising took place against Musayyah, who was superseded by El-Fadhl ibn Sulaymān Tūsī in the governorships of Khorāsān and Sīstān.
A.H. 167 (783). Death of El-Mahdi. Succession of El-Hādi.
A.H. 170 (786). Death of El-Hādi. Succession of Hārūn er-Rashīd.
A.H. 171 (787). Ja`far el-Ash`ath, governor of Khorāsān.
A.H. 172 (788). El-`Abbās el-Ash`ath followed his father as governor, and was, A.H. 175 (791), succeeded by his uncle El-Ghatrīf ibn `Atā.
A.H. 176 (792). Shi`ite revolt in Daylam. Hamza el-Khuzā`ī, governor of Khorāsān.
A.H. 178 (794). El-Fadhl ibn Yahya was appointed governor of Khorāsān.
A.H. 178 (794). He built mosques and post-stations in Khorāsān, conducted a “Holy War” in Transoxiana, and was unsuccessfully attacked by the king of Oshrūsana Khārakhara.[199]