Ali ibn Husayn Zayn al-Abidin

Ali al-Sajjad was born around 658, great-grandson of Muhammad and son of Husayn ibn Ali. In 680 he witnessed the Battle of Karbala, where Umayyad forces slaughtered his father's small caravan en route to Kufa; he was one of the few to survive. Taken to Damascus and treated poorly, he was eventually permitted to return to Medina. There he withdrew from the pro-Alid rebellions of the Second Fitna and devoted himself to worship and scholarship, becoming a respected authority on hadith and fiqh even among proto-Sunnis. He remained politically quiescent and drew few followers until late in life, as many Shia initially rallied to Mukhtar al-Thaqafi's armed resistance. He died around 712, possibly poisoned by the Umayyads. The mainstream Shia then followed his eldest son Muhammad al-Baqir; others followed his much younger son Zayd ibn Ali, whose failed rebellion in 740 gave birth to Zaydism.