 Al @-@ Tabari describes al @-@ Mu 'tasim as having a relatively easygoing nature , being kind , agreeable and charitable , while according to the Orientalist C.E. Bosworth , " Not much of [ al @-@ Mu 'tasim 's ] character emerges from the sources , though they stress his lack of culture compared with his brother al @-@ Ma 'mun , with his questing mind ; yet al @-@ Mu 'tasim 's qualities as a military commander seem assured , and the Abbasid caliphate remained under him a mighty political and military entity " . 
