Graunt's analysis of the London bills of mortality showed that the population of London would merit further study. However, conclusions based on the bills of mortality will always be open to question because it is not possible to verify the aggregate totals of baptisms and burials which are not subdivided by parish. A serious reconsideration of the parish registers in association with which the bills were compiled is thus called for. In a recent review of urban history during the early modern period, J. Patten (1978: 18) wrote that ‘until far more work is done on the direct evidence of parish registers, it will be hard to consider actual population dynamics and growth in detail and on any scale’. But it is often thought that the reliability of the London parish registers is doubtful. For example, I. Sutherland commented that ‘family reconstitution studies on the London parish registers do not appear to be a practical proposition’. He went on to explain his reasons for this view (1972: 310–11).

It is evident that if the London parish registers are to be used for population studies, their reliability must be assessed.