This project will achieve a greater and more nuanced understanding of the unprecedented English and Welsh fertility decline of the Victorian and Edwardian periods through the production of an Atlas of Fertility which will illustrate geographical patterns in various measures of fertility and marriage over time. Despite considerable research into the late 19th and early 20th century decline of fertility in England and Wales, understanding of the origins and evolution of this important social development remains surprisingly limited, mainly because researchers have largely had to rely on published reports (which tabulate figures for large geographic units and give no information on how fertility is distributed among women) or on time-consuming local studies. Now, however, the release of a database of individual-level census returns for the whole of England and Wales for 1851-1911 makes feasible the calculation of age specific fertility measures at 7 points in time for over 2000 registration sub-districts (RSDs), as well as for social classes and occupational groups. Such measures will greatly enhance our knowledge of where, when and at what rate fertility declined, and which groups spearheaded the behaviours which reduced the number of children being born. To calculate age-specific fertility rates from the returns of a particular census, an estimate of the number of children born to women of specific ages in the 5 years before the census is required. The number of children aged under 5 living with their mothers can be identified from the census schedules, but additional data on children born in the 5 years before the census but dying before they could be enumerated, or living apart from their parents, have to be included in the counts in order to accurately estimate the fertility rates. The numbers of child and infant deaths for each RSD was therefore collected from the annual and quarterly Registrar General's reports, creating a mortality database at unprecedented geographic scale. Other measures related to fertility have been calculated and mapped, including illegitimacy and children living in single parent families; indices of age structure, migration, and age of marriage; and a variety of socio-economic indicators. A spatial database of fertility, marriage and early child mortality has been constructed at RSD level, allowing patterns to be mapped and spatially and statistically analysed. The maps also form the basis of the online 'Atlas of Victorian and Edwardian Population': www.populationspast.org (aimed at schools and the general public, as well as academic audiences) where they are complemented with explanatory text and activities. Academic outputs use multivariate spatial analyses to investigate the influences affecting fertility, nuptiality and early age mortality, and the results are published in leading academic journals. The project also compares the cross-sectional fertility measures, derived by counting parents and their children in the census returns, with the fertility rates reported retrospectively by married women in the 1911 census. The Atlas and academic papers provide very detailed data, allowing the 'big questions' about fertility decline in England and Wales (Where did fertility decline start? Did it spread mainly through social groups or over geographical space?) to be addressed more thoroughly than ever before.