The work represented in this book has spanned many years and two hemispheres, and my indebtedness for help and advice is correspondingly wide-ranging. Two institutions have provided complementary, equally congenial atmospheres to work in. My friends at the Cambridge Group for the History of Population and Social Structure laid the foundations for my understanding of social-science history and unfailingly welcome my annual return. My students and colleagues at The Catholic University of America continue to point out that I always have more to learn.

I owe even greater debts to many individuals who have helped my Essex research along. Richard Smith first started me out on this path, and spent much time commenting on my research and text. Roger Schofield's keen editorial scrutiny likewise helped me avoid running aground upon many shoals. The book would have been less than it is without information and specialist insights generously provided by Jeremy Boulton, Bruce Campbell, Richard Helmholz, Anne Hudson, Ray Powell, Andrew Prescott, Steve Rappaport, Michael Sheehan, David Souden and M. C. Wadhams. The text has greatly benefited from close reading and commentary by Richard Britnell, Elaine Clark, Barrie Dobson, Christopher Dyer, Michael Gervers, Jo Ann Hoeppner Moran, Jon Wakelyn and Richard Wall. My mistakes remain my own.

Financial support for portions of my research came from the British Academy, the Ellen McArthur Fund of the Cambridge University Faculty of History, and the American Bar Foundation. Catholic University's special projects fund contributed to the costs of preparing illustrations.