The Nāṣirī Generations 10: I. TAHIR-I-ZU-L-YAMANAIN.

10

Ibn Haisam, the chronicler, and author of the work entitled “Kasas-i-Sani,” whose patronymic appellation was Abu-l-Hasan, and his name Haisam, son of Muhammad, Al-Baki [Nabi ?] states, that, when the Commander of the Faithful, Mamun, removed Ghassan, son of ’Ubbad, from the government of Khurasan, he conferred it, together with the government of ’Ajam, upon Amir Tahir; and that As’ad, the grandfather of Tahir, before his conversion to the Muhammadan religion, bore the name of Farrukh. He was converted to the faith by Talhah, who gave him the name of As’ad ; and he had a son whom he named Mus’ab ; and he, Mus’ab, became resident at Fushanj. When the claims of the family of ’Abbas to the Khilafat were put forward, this same Mus’ab became one of the principal men and partisan leaders of that dynasty. Mus’ab had a son, Husain by name, which Husain, for a considerable time, administered the affairs of Fushanj, and was its Wali [governor] ; and Tahir [Zu-l-Yamanain] was his son ; and these successes, which have been mentioned, were gained by this same Tahir.
When Mamun came to Baghdad, to assume the Khilafat, he despatched Tahir to Rakk’ah, to carry on hostilities against Nasr-i-Shis. Subsequently to this he came into Khurasan; and, in 207 he died, having nominated his son Talhah, son of Tahir, his Khalifah or successor.
The chronicler relates, that on the Friday he read the Khutbah, and either forgot to mention the name of Mamun, or omitted it purposely. After he had returned to his residence at night, and had retired to rest, at daybreak of Saturday morning he was found in his bed asleep in death; and it was never known how or from what, his death originated.