During the Caliphate of Mutawakkil[218] the government of the province of Sīstān was usurped by a man named Sālih ibn Nasr, who, under the pretext of putting down a rising of the Khārijites, had gathered round himself a large body of adherents. The then governor of Khorāsān, Tāhir II., hearing of the disorders in Sīstān, took the field in person in order to put an end to the hostilities between the Khārijites and Sālih’s adherents. This he succeeded in doing, but scarcely had he returned to his residence when news reached him that Sālih had again taken the field. Among the lieutenants of the latter was a certain Ya`kūb ibn Layth, who was destined to play an important part in the history of his time, and to establish a powerful though short-lived dynasty. He is one of the most popular heroes of Persian history, and so many anecdotes have clustered round his name that it is difficult to separate truth from romance. His origin was certainly obscure, and he appears to have been the son of a coppersmith,[219] though authorities are divided as to whether he ever plied that trade himself.[220] Many tales are told of his reckless generosity as a boy, and his consequent popularity among his schoolfellows. His Persian biographers tell us, without apology or comment, that on reaching the age of adolescence he became a highway robber; and he was doubtless followed by those whom his masterful bearing had attached to his person during childhood. “The number and character of his followers, and the success of his enterprises, soon gave him fame and wealth, and his generous and humane usage of those whom he plundered added to his renown and popularity. In such a state of society the transition from the condition of a successful robber to that of a chief of reputation was easy and natural. A man who possessed activity and courage, and who was able to command a number of adherents, could not fail of early attaining rank and consequence.”[221] Sālih was only too glad to obtain the services of the bold highwayman, who rose so rapidly to power that the governor’s successor, Dirham ibn Nasr, in A.H. 247 (861), gave him command of his army, which henceforth became the terror of the surrounding countries. Meanwhile the Tāhirides remained inactive in Nīshāpūr, and followed a policy of _laissez-faire_ which wrought their downfall.