Muhammad al-Taqi

Abu al-Husayn Ahmad ibn Abd Allah ibn Muhammad ibn Isma'il, commonly known as Muhammad al-Taqi, was a descendant of the Islamic prophet Muhammad and the ninth of the Isma'ili Imams, succeeding his father, Ahmad al-Wafi. Like his father, he lived primarily in Salamiyah, and Abd Allah ibn Maymun al-Qaddah, the chief missionary, continued to serve as the hijab for him. Known by the title Ṣāḥib al-Rasāʾil, al-Taqi is said to have prepared with his followers an encyclopedic text called the Encyclopedia of the Brethren of Purity. He died in 840 in Salamiyah and was succeeded by his son al-Husayn.