 From ca . 814 / 5 , Abu Ishaq began forming his corps of Turkish troops . The first members of the corps were domestic slaves he bought in Baghdad ( the distinguished general Itakh was originally a cook ) whom he trained in the art of war , but they were soon complemented by Turkish slaves sent directly from Central Asia after an agreement with the local Samanid rulers . This private force was small — it probably numbered between three and four thousand at the time of his accession — but it was highly trained and disciplined , and made Abu Ishaq a man of power in his own right , as al @-@ Ma 'mun increasingly turned to him for assistance . Abu Ishaq 's Turkish corps was also politically useful to al @-@ Ma 'mun , who aimed to lessen his own dependence on the mostly eastern Iranian leaders who had supported him in the civil war , and who now occupied the senior positions in the new regime . In an effort to counterbalance their influence , al @-@ Ma 'mun granted formal recognition to his brother and his Turkish corps , as well as placing the Arab tribal levies of the <unk> in the hands of his own son , al @-@ Abbas . 
