Ali's father, Isa ibn Mahan, was an early follower and da'i of the Hashimiyya; he mutinied after the Abbasid Revolution and was executed by Abu Muslim.
[1] Under Harun al-Rashid (r. 786–809) he continued to serve as commander of the guard until 796, when he was named governor of Khurasan, over the objections of Yahya al-Barmaki.
As many of the Baghdadi elites, he was a strong supporter of the new Caliph, al-Amin (r. 809–813), who honoured him with the appellation shaykh hadhihi'l-dawla ("elder of this dynasty") and put him in charge of the affairs of his own heir, Musa.
[1][2] Of his sons, Isa served his father as deputy governor for Sistan, but was killed by Rafi ibn al-Layth's supporters in 807.
[6] Another son, al-Husayn, also served in Sistan during Ali's governorship of Khurasan, and suppressed an anti-Abbasid rebellion and recruited troops in Syria in 811/2.