Isma'il ibn Ja'far al-Sadiq was the eldest son of the sixth Imam Ja'far al-Sadiq; his mother was Fatima bint al-Husayn ibn Ali al-Athram. He is a central figure in the Isma'ili tradition: by that branch's account the imamate passed from Ja'far to his son Isma'il (and then to Isma'il's son Muhammad ibn Isma'il), and it is from him that the Isma'iliyya take their name. In the Twelver (Ithna'ashari) tradition, however, the imamate continued through Isma'il's brother Musa al-Kazim, because Isma'il died during his father's lifetime, around 138 AH (755 CE) in Medina. Famously, Ja'far al-Sadiq uncovered his son's face before witnesses to refute those who denied his death, an event linked to the concept of bada'. He was buried in Jannat al-Baqi; a domed shrine (built in the Fatimid era) over his grave was demolished in the 1925-26 Baqi demolitions. A minority Isma'ili tradition holds that he outlived his father and was buried at Salamiyah in Syria; this is noted as a sectarian position.