Muhammad al-Baqir

Muhammad ibn Ali, called al-Baqir (an honorific glossed by tradition as "the one who splits knowledge open" or "who possesses vast learning"), with the kunya (paternal by-name) Abu Ja'far, is counted as the fifth Imam by both Twelver and Ismaili Shia Muslims. He was a great-great-grandson of the Prophet Muhammad through Husayn ibn Ali. He was born in Medina, traditionally dated to around 56-57 AH (c. 676-677 CE); his father was the fourth Imam, Ali ibn al-Husayn ("Zayn al-Abidin"), and his mother is reported to have been Fatima, a daughter of al-Hasan ibn Ali.

Sira (biographical tradition) holds that al-Baqir was a small child present at the Battle of Karbala in 61 AH (680 CE), where his grandfather Husayn was killed; reported ages range from about two-and-a-half to four. After his father's death (c. 94-95 AH), most of his father's followers recognised him as Imam.

Modern scholarship credits him with helping lay the legal and doctrinal groundwork later developed by his son Ja'far al-Sadiq. Shia tradition emphasises a quietist stance, focused on teaching rather than rebellion — a contrast often drawn with his half-brother Zayd ibn Ali, whose revolt (c. 122 AH / 740 CE) came after al-Baqir's death and is claimed by Zaydi Shi'ism. He was also esteemed as a hadith transmitter in Sunni circles. He died in Medina around 114 AH (732 CE) and is buried in the Baqi cemetery. Shia reports say he was poisoned, though sources do not agree on details or culprit.