Abdallah al-Aftah
ʿAbdallāh al-Afṭaḥ ibn Jaʿfar al-Ṣādiq was the eldest son of Ja'far al-Sadiq and the full-brother of Isma'il ibn Jafar. Abdallah's title "al-Aftah" derives from the Arabic words "aftah al-ra’s" or "aftah al-rijlayn" used to describe his appearance.
Life
During the lifetime of his father, Abdallah al-Aftah had supported the revolt of his relative Muhammad al-Nafs al-Zakiyya.Following Ja'far al-Sadiq's death, the majority of Ja'far's followers accepted Abdallah al-Aftah as their new Imam. These followers were known as the Fathites and, according to the Mu'tazili heresiographer Abul-Qasim al-Balkhi al-Ka‘bi, they were the biggest and most important section of the followers of Ja'far al-Sadiq. To support his claims, Abdallah al-Aftah seems to have claimed a 2nd Nass from his father and his adherents cited a supposed Hadith from Ja'far al-Sadiq to the effect that the Imamate must be transmitted through the eldest son of the Imam. However, when Abdallah al-Aftah died childless about 70 days after the death of his father, the bulk of his supporters went over to his brother Musa al-Kazim. Other Fathites considered Abdallah al-Aftah the 7th Imam and Musa al-Kazim the 8th Imam, while others believed the Imamate came to an end when Abdallah al-Aftah died. Another group invented a son for Abdallah al-Aftah, called Muhammad ibn Abdallah al-Aftah, because they unconditionally believed the Imamate could only be inherited from father to son, rather than from brother to brother. This group also claimed that Muhammad ibn Abdallah al-Aftah was the promised Mahdi.