JACOB LASSNER is Philip M. and Ethel Klutznick Professor of Jewish Civilization at Northwestern University. He specializes in medieval Near Eastern History with an emphasis on urban structures, political culture, and the background to Jewish-Muslim relations. Michael Bonner is professor of medieval Islamic history in the Department of Near Eastern Studies, University of Michigan, Ann Arbor, MI. He received his PhD in the Department of Near Eastern Studies, Princeton University, in 1987. His recent publications include Jihad in Islamic History: Doctrines and Practices (2006) and Poverty and Charity in Middle Eastern Contexts, co-edited with Amy Singer and Mine Ener (2003). He has been a Helmut S. Stern fellow at the University of Michigan Institute for the Humanities and professeur invité at the Institut d'Etudes de l'Islam et des Sociétés du Monde Musulman, École des Hautes Études en Sciences Sociales, Paris, France and of Chaire de l'Institut du Monde Arabe, also in Paris. He was director of the University of Michigan Center for Middle Eastern and North African Studies in 1997-2000 and 2001-2003, and acting chair of the Department of Near Eastern Studies in 2007-08.