ABŪ ʿABDALLĀH YAʿQŪB B. DĀʾŪD, vizier of the ʿAbbasid caliph Mahdī (r. 158-69/775-85). He professed pro-ʿAlid sentiments and participated in the revolt of the Hasanids Ebrāhīm and Moḥammad b. ʿAbdallāh against the caliph Manṣūr in 145/762-63. Imprisoned, he was set free in 159/775-76 by Mahdī, who sought, by means of a general amnesty, to reconcile the opposing moderate Shiʿites with each other. He soon became the advisor of the caliph, who in 163/779-80 gave him the title “brother in God and vizier” and conferred on him the direction of matters with which Abū ʿObaydallāh had formerly dealt. This was the first official nomination of a vizier that the chroniclers relate, but that does not mean that the title of vizier had not previously been used. Yaʿqūb profited from his position to appoint Zaydī partisans, that is, moderate Shiʿites, throughout the provinces. However, the caliph did not succeed by these means in overcoming the opposition; for their part, the Zaydīs were becoming disillusioned with their former friend who had become vizier. The policy of Mahdī failed; and the caliph, wishing to test the loyalty of his vizier, set a trap for him by asking him to dispose of an ʿAlid who had been arrested. When he learned that Yaʿqūb had let the ʿAlid escape, he became violently angry and had his vizier and the members of his family imprisoned. Yaʿqūb was to remain in prison until the beginning of the reign of Hārūn al-Rašīd. Having become blind, he managed to establish himself in Mecca, where he died in 186/802.


See the indices to Ṭabarī and to Jahšīārī, Ketāb al-wozarāʾ, Cairo, 1938.

Ebn Ḵallekān, no. 840.

D. Sourdel, Le vizirate ʿabbaside, Damascus, 1959-60, index.

(D. Sourdel)

Originally Published: December 15, 1983

Last Updated: July 19, 2011

This article is available in print.
Vol. I, Fasc. 3, p. 251

Cite this entry:

D. Sourdel, “Abu Abdallah Yaqub,” Encyclopædia Iranica, I/3, p. 251; an updated version is available online at http://www.iranicaonline.org/articles/abu-abdallah-yaqub-b (accessed on 26 January 2014).