Historical demography is the study of patterns and changes in a society's population before the collection of data through modern censuses. For Japan, data on family size and structure, fertility and infant mortality, marriage patterns, urban and rural populations, and migration from one region of the country to another have been preserved for several centuries in temple registration documents, population and cadastral surveys conducted by the Tokugawa government from the17th to 19th centuries, and other sources of information. In this volume, Akira Hayami, one of the pioneers of historical demography in Japan, reports on the findings of researchers who are working with these rich sources of data. He explains the importance of their conclusions not only for historical studies but also for understanding the demography of contemporary Japan and its foreseeable future.