Fred M. Donner is Professor of Near Eastern History and Director of the Center for Middle Eastern Studies at the University of Chicago where he teaches on early Islamic history, Islamic social history, and aspects of Islamic law. His work for the past two decades has focused on the origins and rise of what he calls the “Believers’ movement,” begun by Muhammad (d. 632 CE), which was a stringently monotheistic and pietistic reform movement that also included righteous Jews and Christians, but had crystallized into a separate movement that can properly be termed “Islam” by about 680. This thesis is explored in his book Muhammad Among the Believers (Harvard University Press, 2010).