An historian of ideas with a focus on Mediaeval Islamic History, Paul E. Walker has taught at McGill University, Columbia University and the University of Michigan. For several years Dr Walker was the Director of the American Research Centre in Egypt, and is currently a Visiting Scholar with the University of Chicago's Center for Middle Eastern Studies. He has authored and edited many books on Fatimid history and the formative period of Ismaili thought including Early Philosophical Shi'ism (Cambridge University Press, 1993), The Wellsprings of Wisdom: A Study of Abu Yaqub al-Sijistani's Kitab al-Yanabi (University of Utah Press, 1994), Abu Yaqub al-Sijistani: Intellectual Missionary (I. B. Tauris in association with The Institute of Ismaili Studies, 1996), Hamid al-Din al-Kirmani: Ismaili Thought in the Age of al-Hakim (I. B. Tauris in association with The Institute of Ismaili Studies, 1999), with Wilferd Madelung, An Ismaili Heresiography (Brill, 1998) and The Advent of the Fatimids: A Contemporary Shi'i Witness (I. B. Tauris in association with The Institute of Ismaili Studies, 2000). Most recently, Dr Walker is the recipient of the 2001 Guggenheim Fellowship to study the Imam-Caliph al-Hakim.