In writing this book I was heavily dependent on the help of others. I am particularly grateful to Mark Smith for his advice and his patience in answering my questions about Coptic and Egyptology, and to Wadi Abullif for his generous assistance in Cairo. I would like to thank Sydney Aufre`re, Anne Boud’hors, Nathalie Bosson, Charles Libois, and the late Maurice Martin for allowing me to profit from their discoveries and expertise, Colin Wakefield for his help at the Bodleian Library and his advice about Arabic transcriptions, Nigel Hope for his proof correcting and Bonnie Blackburn for her copy-editing. My thanks also go to Anne Ashby, Alice Bailey, Maurits van den Boogert, Anthony Grafton, Nelly Hanna, Johannes den Heijer, Jan Helderman, Karim Ibrahim, Robert Jones, Gautier Juynboll, Ivo Klaver, Jill Kraye, William Lyster, Dorothea McEwan, Ian MacLean, Georges Masson, Peter Miller, Andrew Pettegree, Paul Botley, Jenny Boyle, Francis Richard, Jonathan Rolls, Lydia Salviucci Insolera, Rijk Smitskamp, Gerald Toomer, Hans van der Velde, Michael Walsh, Nicholas Warner, Joanna Weinberg, and Jan Just Witkam. I gratefully acknowledge an S. T. Lee Fellowship at the School of Advanced Study, London University, the subsidies given to me for travel in Egypt by the Leidse Universitaire Fonds, the library and hospitality of the Netherlands-Flemish Institute in Cairo, and above all of the Warburg Institute in London, and, finally, the support of the Dr C. LouiseThijssen-Schoute Stichting, to whose former chairman,A. G. H . Bachrach, this book is affectionately dedicated.