Professor Emeritus

of History and the College

Former Voting Member of the Oriental Institute

Walter Kaegi has retired and no longer directs BA theses or accepts new graduate students.

PhD 1965 Harvard University

Field Specialties

Byzantine and late Roman political, social, military, and religious structures; historiography; European military history and strategy; Byzantino-Islamic history


Walter Kaegi's research concentrates on Byzantine and late Roman history, especially from the fourth through eleventh centuries,with special attention to the seventh century. He investigates relationships between Byzantium and the Near East, including Islam, military and historiographical subjects and their interrelationships with religion and thought. He seeks to set these researches in broader European and Mediterranean contexts. He is the cofounder of the Byzantine Studies Conference, the editor of the journal Byzantinische Forschungen, and past president of the US National Committee for Byzantine Studies.

Several projects are occupying his research time: he is investigating Byzantine commercial relationships with the Arabian peninsula on the eve of the Islamic conquests. He is preparing an essay on Byzantium in the seventh century for an Oxford University Press handbook to Maximus the Confessor.  He is planning an investigation of the role of Byzantine concepts of strategy in the emergence of concepts of strategy in early modern Europe. He is writing a reassessment of Arnold J. Toynbee as a Byzantine historian.


—"Seventh-Century Identities: The Case of North Africa." In Visions of Community in the Post-Roman World: The West, Byzantium, and the Islamic World, 300–1100, edited by W. Pohl, C. Gantner. and R. Payne, 165–79. Farnham, Surrey, UK, and Burlington, VT, Ashgate, 2012.
Muslim Expansion and Byzantine Collapse in North Africa. Cambridge: Cambridge University Press, 2010.
—"Confronting Islam: Emperors versus Caliphs, 641–c. 850." In The Cambridge History of the Byzantine Empire, c. 500–1492, edited by Jonathan Shepard, 365–94. Cambridge: Cambridge University Press, 2008.
—"The Early Muslim Raids into Anatolia and the Byzantine Reactions under Emperor Constans II." In The Encounter of Eastern Christianity with Early Islam, edited by Emmanouel Grypeou, Mark N. Swanson, and David Thomas, 73–93. Leiden: Brill, 2006.
—Heraclius, Emperor of Byzantium. Cambridge: Cambridge University Press, 2003.
—"The Earliest Muslim Penetrations of Anatolia." In Byzantine State and Society in Memory of Nikos Oikonomides, edited by A. Avramea, A. Laiou, and E. Chrysos, 269–82. Athens: National Hellenic Foundation, Center for Byzantine Studies, 2003.
—"Egypt on the Eve of the Muslim Conquest." In Cambridge History of Egypt, edited by C. Petry, 34–61. Cambridge: Cambridge University Press, 1998.
Byzantium and the Early Islamic Conquests. Cambridge: Cambridge University Press, 1992; paperback, 1995.
—"Some Thoughts on Byzantine Military Strategy." In Hellenic Studies Lecture for Ball State University. Brookline, MA: Hellenic College Press, 1983. Printed separately.
Army, Society and Religion in Byzantium. London: Variorum Revised Editions & Reprints, 1982.
Byzantine Military Unrest 471–843: An Interpretation. Amsterdam and Las Palmas: A.M. Hakkert, 1981.
Byzantium and the Decline of Rome. Princeton, NJ: Princeton University Press, 1968; reprinted, 1970.