One cannot spend nearly twenty years, albeit with intermissions, on a piece of work without incurring a considerable number of debts. As the last stage on a long journey it is a pleasure to acknowledge the most important of these. First and foremost I must thank Dr Gerald Harriss, the supervisor of the PhD thesis on which this book is based, not only for his unfailing help and support while I was his research student, but also for his continued encouragement and friendship afterwards. I am also especially grateful to Professor Sir Geoffrey Elton, who not only began to teach me what history was about when I was an undergraduate, but offered assistance and advice both during and after my time as a research student, and to Professor Sir James Holt, Professor Wallace MacCaffrey, Mr Ralph Bennett, Dr John Morrill and Dr Gillian Sutherland, to all of whom I owe a very great deal. The same is true of my colleagues at New Hall - especially Dr Zara Steiner - both for being prepared to offer a secure job to a semi-retired mother of young children and for subsequent friendship and stimulus. Others to whom I am indebted are Professors John Baker, Christopher Brooke, Barrie Dobson, Roderick Floud (if I failed to take his generous advice on how to do proper statistical tests, it was merely the result of my own mathematical ineptness), Hassell Smith, the late Professor Christopher Cheney, Drs Caroline Barron, George Bernard, Jeremy Boulton, Brendan Bradshaw, Christopher Dyer, Steven Ellis, Steven Gunn, Michael Hicks, Michael K. Jones, Edward Miller, Ruth Morse, Dorothy Owen, Simon Payling, Sandra Raban, Carole Rawcliffe, Miri Rubin, Richard Tuck, Roger Virgoe and Susan Wright.