Daniel Callahan specializes in the history of Medieval Europe in the tenth and eleventh centuries. He received his B.A. from St. John’s Seminary in Brighton, Mass. in 1962, his M.A. from Boston College in 1965 and his Ph.D. from the University of Wisconsin, Madison in 1968. His publications include a number of articles on the writings of Ademar of Chabannes, on the Peace of God movement and on the development of heresy and anti-Judaism in the tenth and eleventh centuries.