(d. ca. 732–43)
Fifth Shii imam. Called al-Baqir, “the splitter” or “the opener” (of knowledge). Began teaching of distinctive Imami Shii law and doctrine. Opposed individual reasoning, stressing the authority of the imam. Respected as a scholar and traditionist by some non-Shiis. Personally ascetic, politically quietist, did not support revolts against Umayyads, but held that the imamate was explicitly designated by God. Politically overshadowed by his half-brother Zayd, whose revolt failed, and by proto-Abbasid forces. Had his authority claimed by some Shii extremist groups. Means and date of death are disputed; there are reports of poisoning by Umayyads or rivals for imamate. Buried in Medina.