 Although the new professional army proved militarily highly effective , it also posed a potential danger to the stability of the Abbasid regime : the army 's separation from mainstream society meant that the soldiers were entirely reliant on their cash salary ( ʿaṭāʾ ) for their very survival . Consequently , any failure to provide their pay or policies that threatened their position were likely to cause a violent reaction , as became evident a generation later during the " Anarchy at Samarra " . The need to cover military spending would henceforth be a fixture of caliphal government , and that at a time when government income began to decline rapidly — partly through the rise of autonomous dynasties in the provinces and partly through the decline in productivity of the lowlands of Iraq that had traditionally provided the bulk of tax revenue . Eventually , this would lead to the bankruptcy of the Abbasid government and the eclipse of the caliphs ' political power with Ibn Ra 'iq 's rise to the position of amīr al @-@ umarāʾ in 935 . 
