So far as is known there was no precedent in the experience of England and Ireland for population increase as rapid or as sustained as that which appears to have begun in England in the 1750s and in Ireland some thirty years later If the available figures can be trusted the number of Englishmen (and Welshmen) more than doubled between 1750 and 1831 and the number of Irish living in Ireland doubled between 1780 and 1841. In England the rapid growth of population provides an essential part of the explanation of the coming of the industrial revolution. In Ireland it did even more than largely determine the magnitude of the catastrophe of the Famine. It was unbridled population growth, succeeded by famine, which incised on the minds of the Irish and their rulers unforgettable lessons which guided their conduct in the following century and ensured that Irish economic and social development, moulded by the exigencies of a declining population, should provide a unique model for the historian—and one which he has examined all too little.

It is tantalising that the elucidation of the dimensions and the structure of a problem of such overriding importance should be so elusive. The elusiveness, of course, must largely be attributed to the non-existence or the inadequacy of the appropriate statistics. It was not until half a century after the growth of population had begun that parliament at last insisted that the people be counted regularly.