This study grew out of a thesis submitted in 1948 for the degree of Ph.D. in the University of London, and my first thanks are due to that institution which, by awarding me the Derby Postgraduate Studentship, enabled me to undertake the necessary research. Since those days, however, the book has undergone many changes: it has twice been completely rewritten, gaining (I fear) in length and (I hope) in depth. Much of this revision was done in response to the criticisms of Professor J. E. Neale under whose guidance I took my first steps in historical enquiry; my debt to him is very great. I wish also to record my profound gratitude to my parents who read both typescript and proofs and were ever ready with a comforting mixture of criticism and encouragement; to my friend, Mr E. L. C. Mullins, who likewise spared time from his own heavy commitments to read the book in an earlier guise; to Professor S. T. Bindoff whose vast knowledge is always so readily available to all who are prepared to impose on his kindness; to Mr J. Hurstfield with whom I have often discussed the court of wards; and to many others at the Institute of Historical Research, my seniors and contemporaries, who suffered so patiently the frequent intrusion of Thomas Cromwell into the conversation. As one who attended that institution in the years 1946 and 1947, I should like to mention my particular debt to Professor V. H. Galbraith.