David S. Bachrach is professor of medieval history at the University of New Hampshire. His research focuses on the military and administrative history of Carolingian East Francia/ Ottonian Germany in the ninth-eleventh century and the kingdom of England in the thirteenth and early fourteenth century. He is the author of more than 60 scholarly articles and a dozen books, including Religion and the Conduct of War c. 300-c.1215 (Woodbridge, 2003); Warfare in Tenth-Century Germany (Woodbridge, 2012); and Administration and Organization of War in Thirteenth-Century England (London, 2020). Bernard S. Bachrach, a fellow of the Medieval Academy, is professor emeritus of medieval history at the University of Minnesota. His research focuses on the military history of pre-Crusade Europe. He is the author of more than 160 scholarly articles and 25 books, including Early Carolingian Warfare: Prelude to Empire (Philadelphia, 2002); Charlemagne’s Early Campaigns (768-777): A Diplomatic and Military Analysis (Leiden, 2013); and Writing the Military History of Pre-Crusade Europe: Studies in Sources and Source Criticism (London, 2020), with David S. Bachrach.