The title “Aga Khan” was first given in 1818 to the 46th imam of the Nizārī Ismāʿīlīs by the Persian Qājār king Fatḥ ʿAlī Shāh. Both words mean “master” or “lord” in Turkic languages. The Aga Khan I claimed direct descent of his imamate from ʿAlī, son-in-law of the Prophet Muhammad, and ʿAlī’s wife Fāṭimah, Muhammad’s daughter. The Nizārī Ismāʿīlīs are a branch of the Ismāʿīliyyah sect of Shiʿi Islam.