Muhammad al-Baqir

Muhammad ibn Ali al-Baqir (; ) was the fifth imam in Shia Islam, succeeding his father, Ali al-Sajjad, and succeeded by his son, Ja'far al-Sadiq. His mother, Umm Abd Allah Fatima, was the daughter of Hasan, making al-Baqir the first imam who descended from both grandsons of Muhammad, namely, Hasan and Husayn.

Al-Baqir was born in Medina, about the time when Mu'awiya I () was working to secure the succession of his son, Yazid. As a child, al-Baqir witnessed the tragedy of Karbala, in which all of his male relatives were massacred, except his father who was too ill to participate in the fighting. As a young man, al-Baqir witnessed the power struggles between the Umayyads, Abd Allah ibn al-Zubayr, and various Shia groups, while his father resigned from political activities.

Al-Baqir is revered by both Shia and Sunni Muslims as an eminent expert in jurisprudence, the exegesis of the Quran, the science of hadith, and theology. Though he was a resident of Medina, his main following was in Kufa, Iraq, where he attracted a number of distinguished theologians. Al-Baqir is credited with laying the foundations of Twelver Shia, including a coherent theory of imamate, which was further developed by his son and successor, Jafar al-Sadiq. Like his father, al-Baqir adopted a policy of quiescence, and reportedly attempted to dissuade his half-brother, Zayd, from prematurely revolting against the Umayyads.

According to Tabataba'i, al-Baqir was poisoned by Ibrahim ibn al-Walld, during his brief reign. Though 114 AH (732) and 117 (735) are commonly reported, there are different views about the date and cause of al-Baqir's death. Provided by Wikipedia