The Ismailis consist of two main branches the' Nizari Ismailis and the Musta'lian Tayyibi Ismailis. Both have their roots in the Fatimid period of Ismaili history and differ primarily over their respective belief in the Imamat. that is, spiritual leadership of the community.
The Nizari branch believes in a living, physically present Imam. Their present and forty-ninth Imam is Prince Karim Aga Khan. The Musta'lian Ismailis believe that their twenty-first Imam, al-Tayyib, went into physical concealment (satr) and that while the Imamat continues in his line, authority in his physical absence is exercised by a vicegerent, da'i mutlaq, who acts on his behalf. In their encounter with modernity therefore, the two communities reflect a different pattern of historical and institutional development.
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. Prior to this, he was Professor and Chair of the Department of Religion at the University of Florida and has held academic and administrative appointments at various American and Canadian universities.
Professor Nanji has authored, co-authored and edited several books including: The Nizari Ismaili Tradition (1976), The Muslim Almanac (1996), Mapping Islamic Studies (1997) and The Historical Atlas of Islam (with M. Ruthven) (2004) and The Dictionary of Islam (with Razia Nanji), Penguin 2008. In addition, he has contributed numerous shorter studies and articles on religion, Islam and Ismailism in journals and collective volumes including The Encyclopaedia of Islam, Encyclopaedia Iranica, Oxford Encyclopaedia of the Modern Islamic World, and A Companion to Ethics. He was the Associate Editor for the revised Second Edition of The Encyclopaedia of Religion. In 1988 he was Margaret Gest Visiting Professor at Haverford College and a Visiting Professor at Stanford University in 2004, where he was also invited to give the Baccalaureate Address in 1995 (see Baccalaureate Address at Stanford University). He has also lectured widely at international conferences all over the world.
Professor Nanji has served as Co-Chair of the Islam section at the American Academy of Religion and on the Editorial Board of the Academy’s Journal. He has also been a member of the Philanthropy Committee of the Council on Foundations and has been the recipient of awards from the Rockefeller Foundation, the Canada Council, and the National Endowment for Humanities. In 2004 he gave the Birks Lecture at McGill University.
Within the Aga Khan Development Network, Professor Nanji has served as a Member of the Steering Committee and Master Jury of the Aga Khan Award for Architecture, Task Force Member for the Institute for the Study of Muslim Civilisations (AKU-ISMC) and Vice Chair of the Madrasa-based Early Childhood Education Programme in East-Africa.
Zulfikar Hirji is an Anthropologist and Social Historian of Muslim Societies and Cultures. He is currently Associate Professor of Anthropology at York University, Toronto. He was formerly a Research Associate at The Institute of Ismaili Studies, London, and Junior Research Fellow at Wolfson College, Oxford.