(born 699/700, Medina, Arabia — died 765, Medina) Sixth
imam of the
Shi'ite branch of Islam and the last to be recognized by all the Sh
i'ite sects. He was the great-grandson of
'Ali. As a possible claimant to the caliphate, Ja'far was viewed as a threat to both the
Umayyad and
'Abbasid 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
Abu Hanifah. After his death the Sh
i'ites began to splinter. One sect, the
Isma'iliyyah, became followers of his son, Ismail. Another, the
Ithna 'Ashariyyah, traced a succession from Ja'far to the Twelfth Imam awaited at the Last Judgment.
For more information on Ja'far ibn Muhammad, visit Britannica.com.