Son of Ja‘far al-Sadiq; seventh Twelver Imam
Identity
Musa ibn Ja‘far, known as al-Kazim, is recognized as the seventh Imam by Twelver Shi‘i Muslims. His succession belongs to the history of differing Shi‘i communities after Ja‘far al-Sadiq.
Abbasid rule and imprisonment
The Twelver biography linked below describes repeated pressure from Abbasid authorities and imprisonment in Basra and Baghdad under Harun al-Rashid. It presents his endurance and devotion as central features of his life.
Death and remembrance
He died in 183 AH / 799 CE. Twelver accounts describe his death as poisoning during imprisonment; that attribution should remain explicit. His burial place at al-Kazimayn in Baghdad, shared by the shrine of Muhammad al-Jawad, became an important pilgrimage destination.
Sources and further study
Fourteen Luminaries of Islam — Musa ibn Ja‘far (Twelver biography)
Royal Asiatic Society study — Shi‘i pilgrimage scroll and Kazimayn
An introductory, source-attributed profile. Dates and disputed reports are qualified where necessary. The linked works represent their authors’ historical or religious approaches; linking a source does not endorse every interpretation it contains.