[3] During the lifetime of his father, Abdallah al-Aftah had supported the revolt of his relative Muhammad al-Nafs al-Zakiyya.
However, when Abdallah al-Aftah died childless[6][7] about 70 days after the death of his father, the bulk of his supporters went over to his brother Musa al-Kazim.
In a letter sent to the Isma'ili community in Yemen by the first Fatimid caliph, Abdallah al-Mahdi Billah, which was reproduced by Ja'far ibn Mansur al-Yaman, Abdallah al-Aftah was referred as Sāhib al-Haqq or the legitimate successor of Ja'far al-Sadiq, in an attempt to explain the genealogy of his ancestors.
According to al-Mahdi Billah, al-Aftah had called himself 'Isma'il ibn Ja'far' for the sake of taqiyya, and each of his successors had assumed the name Muhammad.
But the Imamah (Ismaili doctrine) was later formulated in a different manner since ʿAbdallah al-Mahdi Billah's explanation of his ancestry was not accepted by his successors.