Georgios Chatzelis is currently a teaching fellow at Democritus University of Thrace and at Hellenic Open University. In the past, he held research and teaching positions at Royal Holloway University of London, Aristotle University of Thessaloniki, Centre for Advanced Study Sofia and New Europe College: Institute for Advanced Study. His recent publications include Byzantine Military Manuals as Literary Works and Practical Handbooks: The Case of the Tenth-Century Sylloge Tacticorum (2019) and, with Jonathan Harris, A Tenth-Century Byzantine Military Manual: The Sylloge Tacticorum (2017).Jonathan Harris is Professor of the History of Byzantium at Royal Holloway, University of London. His recent publications include Byzantium and the Crusades, third edition (2022); Introduction to Byzantium (602–1453) (2020) and The Lost World of Byzantium (2015). His first novel, Theosis, appeared in 2023 and he is currently editing The New Oxford Illustrated History of the Crusades.