The Armies of al-Mamūn in Khurāsān (193-202/809 — 817-18): Recruitment of its Contingents and their Commanders and their Social-Ethnic Composition

The following subjects are elaborated on in this article: a) The recruitment of commanders and military units in Marw. The most important was Ṭāhir b. al-Ḥusayn and other members of his family; b) The mobilization of a non-Arab army from Khurāsān and Transoxiana; c) A discussion on the three chief commanders of al-Maʾmūn (and also others), Ṭāhir b. al-Ḥusayn, and two of the most honoured commanders of al-Abnāʾ, Harthama b. Aʿyan and Zuhayr b. al-Musayyab b. Zuhayr; d) The armies of al-Ḥasan b. Sahl in al-ʿIrāq from 198 or 199/813-814, which at the beginning mainly consisted of the armies of Harthama and Zuhayr b. al-Musayyab, the Abnāwīs; e) The stiff opposition to al-Maʾmūn and to al-Faḍl b. Sahl in Khurāsān. A notable opposition to al-Maʾmūn and al-Faḍl b. Sahl was that of Harthama b. Aʿyan and another senior Abnāwī. It seems that the main reason for this opposition, which eventually ended in Harthama's execution in Marw, was his opposition to the murder of al-Amīn that was carried out with the agreement and approval of al-Maʾmūn. Close study of the evidence on the senior commanders who were sent by al-Maʾmūn from Marw to al-ʿIrāq (between 200-203/815-818) reveals that most of them were in fact Arabs, or belonged to veteran families of the Abnāʾ. Only rare information is given about the ethnic nature of their contingents; there is no evidence of non-Arab commanders or troops sent from Marw.