This is not the book that I originally set out to write; had it been so it would have been completed far sooner. Instead, it is the book to which I have been led by a fortuitous succession of research projects; for research, once begun, has a habit of assuming a momentum of its own. Rather than charting a straight and direct course to a predetermined destination it has been a case of seizing opportunities and following where they lead. My original agenda and techniques have also been overtaken by a fast-changing historiography and the advent of increasingly powerful personal and lap-top computers and menu-driven software which have transformed the potential for data collection and analysis. Evolving an appropriate methodology, including robust methods of classification, has also been a matter of trial and error. With hindsight I can see how more data could have been collected more systematically and analysed and classified more rigorously. Nevertheless, I have resisted the temptation to act like Penelope at her loom. Instead, I offer what I have done, uneven though it is, in the hope that others will improve upon and extend it: there are many unexplored and unresolved issues and the wealth of underutilized and unexamined archives is great.

My original aim was to write a book about seigniorial agriculture in medieval Norfolk but set in a broader regional and national perspective. The Norfolk accounts database (Appendix 2) was therefore the first to be constructed of the core databases upon which this book is based. Work on it was ongoing throughout the 1970s and early 1980s, aided by periods of study leave and successive grants from the Research and Scholarships Fund of The Queen's University of Belfast.