ABSTRACT
The Arab sources give much importance to the conspiracy of ‘Abbās, the son of Ma’mūn, against the caliph Mu‘taṣim in 838. Many pages of the history of Ṭabarī are devoted to explaining how the conspiracy took form during the expedition against Amorion. 1 When his father Ma’mūn died in 833, ‘Abbās, despite the protests of some of his followers who hailed him by the name of caliph, gave his allegiance to Mu‘taṣim, Ma’mūn’s brother. He was probably trying to avoid a new dispute over the caliphate that would reproduce the civil wars of the 820s. However, disaffection grew over time between the followers of ‘Abbās, who represented the Arab leaders of the Thugūr (he was the governor of these military frontierlands) as well as the Khurāsānis and Abnā’ of Baghdad (the traditional supporters of the Abbasids), and the new military commanders promoted by Mu‘taṣim among the Turkish soldiers, who felt a personal commitment to the new caliph. 2 Thus a conspiracy coalesced around ‘Abbās that aimed at killing Mu‘taṣim and his most loyal generals Afshīn and Ashnās.
