Alptakin was then taken to Cairo in Egypt , where he was greatly treated by al - Aziz , but was later poisoned by the latter 's '' vizier '' , Yaqub ibn Killis .
Alptakin was then taken to Cairo in Egypt , where he was greatly treated by al - Aziz , who incorporated Alptakin along with his Turkish followers into the Fatimid army . 
 However , Alptakin was later poisoned by al - Aziz 's '' vizier '' , Yaqub ibn Killis .