 The "Ismā'īlī Imāmate" differ from Twelvers because they had "living imams or da'is" for centuries.They followed Isma'il ibn Jafar, elder brother of Musa al-Kadhim, as the rightful Imam after his father Ja'far al-Sadiq.The Ismailis believe that whether Imam Ismail did or did not die before Imam Ja'far, he had passed on the mantle of the imāmate to his son Muḥammad ibn Ismā'īl al-Maktum as the next imam.