Roger S. Bagnall is Professor of Classics and History at Columbia University. He has edited numerous papyri and ostraka and his previous publications include Reading Papyri, Writing Ancient History (1995), The Demography of Roman Egypt (1994) and Egypt in Late Antiquity (1993). Peter Derow is Hody Fellow and Tutor in Ancient History at Wadham College, Oxford and Lecturer in Ancient History in the University of Oxford. He has published on Hellenistic history and epigraphy and Roman republican history, and has a special interest in Polybius and dealings between Rome and the Greeks. He is co-editor with Robert Parker of Herodotus and his World: Essays from a Conference in Memory of George Forrest (2003).