More debts have been accumulated before and during the (rather too many) years of this book's preparation for justice to be done to them in a short preface, but a number stand out for special mention. The first are to those who interested me in medieval history when I came up to Cambridge as an undergraduate: Christine Carpenter, Rosamond McKitterick and Sandra Raban. More recently, I have profited greatly from the wise advice of many scholars, especially Valerie Flint, Jonathan Riley-Smith and Miri Rubin. Magdalene College, where this book was begun during a research fellowship and where I have finally finished it as a teaching fellow, has proved the most congenial of environments in which to think and work. Special mention must be made of my immediate colleagues at Magdalene, Eamon Duffy, who kindly read and commented on sections of the book in early drafts, and Tim Harper, for the help they have rendered over the years. Seminars in Norwich, London, Bristol and Aberystwyth have offered further indispensable opportunities to test ideas, expose false assumptions and absorb invaluable advice. The manuscript of the book has benefited from the sharp eyes of a number of readers. My former research student Tom Licence bravely read the whole and saved me from many errors and infelicities. It hardly needs to be said that the remaining deficiencies of substance and style are the work of the author alone. Two final and very substantial debts remain to be acknowledged.