JOHN MATTHEWS is Professor Emeritus of Classics and History, Yale University, USA. He received his PhD from Oxford University in 1969 and taught Greek and Roman history at Oxford for many years before moving to Yale in 1996. He was elected Fellow of the British Academy in 1990. He is author of many books including Western Aristocracies and Imperial Court, A.D. 364-425, The Roman Empire of Ammianus, Laying Down the Law: A Study of the Theodosian Code, and Roman Perspectives: Studies in the social, political and cultural history of the First to Fifth Centuries. He is also co-author of the acclaimed Atlas of the Roman World.