Background
Khuzayma was the son of Khazim ibn Khuzayma, a Khurasani Arab who became an early follower of the Abbasids and played an instrumental rule in their rise to power both during and after the Abbasid Revolution.
Khuzayma was the son of Khazim ibn Khuzayma, a Khurasani Arab who became an early follower of the Abbasids and played an instrumental rule in their rise to power both during and after the Abbasid Revolution.
Abdallah served as chief of security (sahib al-shurta) for the Caliph al-Mahdi (r 775–785) in 781 Civil Engineering, for al-Mahdi"s son and heir-apparent al-Hadi (r 785–786) during his campaign in Jurjan. Caliph Harun al-Rashid (r 786–809) appointed him governor of Tabaristan on the Caspian Sea. As al-Ma"mun"s forces laid siege to Baghdad in 812, he and his family abandoned the city and fled to nearby Mada"in.