This book has taken a long time to reach its present form. It began as part of my doctoral thesis, ‘The Muslims of Norman Sicily, c. 1060–c.1194’, in the Faculty of Modern History at Oxford in 1983. Six years later, while I was Lecturer in Early Islamic Archaeology in the University of Newcastle upon Tyne, I completed the first draft of what was then called ‘Duana Regis: Arabic administration and Norman kingship in Sicily’. A second, heavily revised draft, known as both Duana Regis II and Duana Regia – and referred to as ‘forthcoming’, ‘imminent’ and even ‘in press’, by myself and over-trusting friends and colleagues – was produced in 1989, circulated in typescript, and then shelved. In 1990, Duana Regia returned with me from Newcastle to Oxford. On three or four occasions thereafter, during long vacations or terms of sabbatical leave, individual chapters were revised, but the whole remained incomplete. In the end, only by persuading the University and Wolfson to grant me a full sabbatical year ‘in anticipation of the allowance’, and by ‘mortgaging’ myself to the University until well into what was then the next millennium, was I able to revise and to rewrite the whole book so swiftly that by the time I reached the end I was still content with the beginning. To all those who, for nearly twenty years, have kindly continued to express an interest in this tardy book, I offer sincere apologies, but no excuse except that it is better now than it would then have been.