The present essay is the product of a co-operative enterprise. Several years ago, while working on the records of the Bishops' of Winchester estates, one of the authors, Mr Postan, was struck by the apparent fluctuations in the numbers of recorded heriots. Several possible explanations occurred to him then, including of course variations in harvests. Such evidence of crops as he then collected appeared to support that hypothesis and to suggest a striking parallel with some well-known trends abroad. He nevertheless decided not to pursue the enquiry until he or somebody else had been able to investigate the history of the Winchester estates in greater detail. Subsequently, he noticed similar fluctuations on some other estates, especially on those of Glastonbury. When, two years ago, Mr Titow, then a research student in the University of Cambridge, embarked on the history of the Winchester estates in the thirteenth century, Mr Postan suggested to him that an enquiry into heriots might be one of his tasks. Mr Titow accordingly extracted from the Winchester bailiff's accounts of five manors all the evidence of heriots and prices, and the present essay is the result of his and Mr Postan's combined efforts to deal with the evidence thus assembled.

The division of labour has been as follows. The main table (Table 9.1) and the graphs are the work of Mr Titow, although the eventual shape of both is the result of protracted consultations between the authors.