Mustaali

The Musta‘lī (Arabic: مستعلي‎) Ismā'īlī Muslims are so named because they accept Al-Musta'li as the nineteenth Fatimid caliph and legitimate successor to his father, al-Mustansir. In contrast, the Nizāriyya Muslims – presently headed by the Aga Khan – believe the rightful nineteenth caliph was Musta‘lī's elder brother, Nizār.