 The sack of Amorium brought al @-@ Mu 'tasim much acclaim as a warrior @-@ caliph and <unk> , and was celebrated by contemporaries , most notably in Abu Tammam 's poems . The Abbasids , however , did not follow up on their success . Warfare continued between the two empires with raids and counter @-@ raids along the border , but after a few Byzantine successes a truce was agreed in 841 . At the time of his death in 842 , al @-@ Mu 'tasim was preparing yet another large @-@ scale invasion , but the great fleet he had prepared to assault Constantinople perished in a storm off Cape <unk> a few months later . Following al @-@ Mu 'tasim 's death , warfare gradually died down , and the Battle of Mauropotamos in 844 was the last major Arab – Byzantine engagement until the 850s . 
