This book had its origins when we combined our interests in historical demography (S.S.) and in the modelling of biological systems (C.J.D.). We discovered that the parish registers of England from 1550 to 1812 contain very valuable data series which were readily studied by the statistical technique of time-series analysis, providing a fully quantitative and statistical approach to studies in human demography in the past. The results were ideal for the mathematical modelling of population cycles. We hope that this novel approach to the integration of historical demography and the epidemiology of infectious diseases will be of value to readers from a variety of disciplines.

We are grateful to the following for their encouragement and advice: Professor D. J. P. Barker, Dr D. Baxby, Dr Mary Dobson, Dr C. Galley, Professor Sir Robert May, FRS, Mr I Oeppen, Dr M. I Power, Dr G. Twigg and Professor R. I. Woods.

Our most profound thanks go to Dr S. R. Duncan of the University of Manchester Institute of Science and Technology, our co-author on many papers, for his unstinted assistance and advice. He introduced us to the intricacies of time-series analysis and dealt with all our mistakes in the early days with endless patience; he developed the mathematical modelling which forms a major part of this monograph. Without his continuing help, this book would not have been written.