Rosamond McKitterick is Professor of Medieval History at the University of Cambridge and a Fellow of Sidney Sussex College. Her previous publications include History and Memory in the Carolingian World (Cambridge University Press, 2004), Perceptions of the Past in the Early Middle Ages (2006) and Charlemagne: The Formation of a European Identity (Cambridge University Press, 2008).

John Osborne is Professor of Art History at Carleton University, Ottawa. He is a medievalist and cultural historian who has published widely on the art and architecture of Rome and Venice between the third and sixteenth centuries.