born 699/700, Medina, Arabia
died 765, Medina
Sixth imam of the Shīite branch of Islam and the last to be recognized by all the Shīʽite sects.
He was the great-grandson of Alī . As a possible claimant to the caliphate, Jaʽfar was viewed as a threat to both the Umayyad and Abbāsid dynasties. He traveled to Baghdad in 762 to prove to the caliph that he was not seeking power, then returned to his native Medina, where his pupils included Abū Hanīfah . After his death the Shīʽites began to splinter. One sect, the Ismāīliyyah , became followers of his son, Ismail. Another, the Ithnā Ashariyyah , traced a succession from Jaʽfar to the Twelfth Imam awaited at the Last Judgment.