Barbero, Alessandro. Charlemagne: Father of a Continent. Translated by Allan Cameron. Berkeley: University of California Press, 2004.

Collins, Roger. Early Medieval Europe, 300–1000. 3rd ed. New York: Palgrave Macmillan, 2010.

Delbrück, Hans. The Barbarian Invasions. Vol. 2 of History of the Art of War. Translated by Walter J. Renfroe Jr. Rev. ed. Omaha: University of Nebraska Press, 1990.

Dennis, George T., trans. Maurice’s Strategikon: Handbook of Byzantine Military Strategy. Philadelphia: University of Pennsylvania Press, 2001.

Durant, Will. The Age of Faith: A History of Medieval Civilization — Christian, Islamic, and Judaic — from Constantine to Dante, AD 325–1300. Vol. 4 of The Story of Civilization. New York: Simon & Schuster, 1950.

Durant, Will. Caesar and Christ. Vol. 3 of The Story of Civilization. New York: Simon & Schuster, 1944.

Einhard. The Life of Charlemagne. Ann Arbor: University of Michigan Press, 1960.

Fell, Christine E., and David M. Wilson, eds. Northern World: The History and Heritage of Northern Europe. New York: Harry N. Abrams, 1987.

Ferrill, Arther. Fall of the Roman Empire: The Military Explanation. London: Thames & Hudson, 1986.

Gibbon, Edward. The History of the Decline and Fall of the Roman Empire. 6 vols. 1766–1788. Reprint ed. New York: Everyman’s Library, 2010.

Gregory of Tours. The History of the Franks. Translated by Lewis Thorpe. London: Penguin, 1974.

Heather, Peter. The Fall of the Roman Empire: A New History of Rome and the Barbarians. New York: Oxford University Press, 2006.

James, Edward. The Franks. Oxford, UK: Basil Blackwell, 1988.

Lendon, J. E. Empire of Honour: The Art of Government in the Roman World. Oxford, UK: Oxford University Press, 1997.

Riche, Pierre. Daily Life in the World of Charlemagne. Translated by Jo Ann McNamara. Philadelphia: University of Pennsylvania Press, 1978.

Suetonius. The Twelve Caesars. New York: Penguin Classics, 2007.

Tacitus. Agricola and Germania. New York: Penguin Classics, 2010.

Ward-Perkins, Bryan. The Fall of Rome and the End of Civilization. Oxford, UK: Oxford University Press, 2005.

Wells, Peter S. Barbarians to Angels: The Dark Ages Reconsidered. New York: W. W. Norton, 2009.

Wickham, Chris. The Inheritance of Rome: Illuminating the Dark Ages, 400–1000. New York: Viking, 2009.

Williams, Hywel. Emperor of the West: Charlemagne and the Carolingian Empire. Reprint ed. London: Quercus, 2011.