“How Ecumenical Was Early Islam?” is the title of a lecture by Fred M. Donner, Professor of Near Eastern History, University of Chicago, in celebration of Roy P. Mottahedeh, Gurney Professor of History, Harvard University, at Harvard’s conference entitlted”Law, Loyalty and Leadership: Roy P. Mottahedeh’s Contribution to Middle Eastern and Islamic Studies at Harvard.” The lecture is available for viewing online at http://cmes.hmdc.harvard.edu/node/3252