Lit. ‘Twelvers,’ the majority branch of the Shi‘i Muslims who acknowledge twelve Imams in lineal succession from ‘Ali b. Abi Talib, after the Prophet Muhammad. Following Imam Ja‘far al–Sadiq (d. 765.) the Ithna ‘Asharis acknowledged his younger son Musa al–Kazim as their Imam while the Isma‘ilis recognised Isma‘il, the eldest son of Imam Ja‘far al–Sadiq, as their Imam.