The Nizari or more properly the Nizari Isma'ili Muslims, like other Shi'i communities, acknowledge 'Ali as imam after the Prophet. The Nizari Ismailis have continued to give allegiance to imams descended from Imam 'Ali, on the basis of the principle of designation (nass) by the imam of the time. As of 1957, His Highness the Aga Kha, Shah Karim al-Hussaini, is the forty-ninth hereditary imam of the Nizari Ismailis.
Professor Azim Nanji serves currently as Special Advisor to the Provost at the Aga Khan University. Most recently he served as Senior Associate Director of the Abbasi Program in Islamic Studies at Stanford University 2008-2010 and also lectured on Islam in the Department of Religious Studies. He was previously the of Director of the Institute of Ismaili Studies from 1998 - 2008.