Muhammad Baqir al-Sadr (آية الله العظمى السيد محمد باقر الصدر) (March 1, 1935 – April 9, 1980) was an Iraqi Shia cleric, philosopher, and ideological founder of the Islamic Dawa Party, born in al-Kazimiya, Iraq. He is the father-in-law of Muqtada al-Sadr and cousin of both Muhammad Sadeq al-Sadr and Imam Musa as-Sadr. His father Haydar al-Sadr was a well-respected high-ranking Shi'a cleric. His lineage goes back to Muhammad, through the seventh Shia Imam, Musa al-Kazim.