These are digital boundaries for the system of counties used in England and Wales for vital registration and also for the administration and reporting of the Census of Population. They were defined as aggregates of Registration Districts and existed only for purposes of statistical reporting. They differed significantly from both Ancient and Administrative Counties, which the same censuses often also reported on. This file represents the system as it was used to report the 1901 Census of Population. Statistical data and other information used in “A Vision of Britain through Time” can be accessed here: http://www.visionofbritain.org.uk/data. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. Great Britain Historical GIS Project. (2012). Registration Counties of England and Wales, 1901. University of Portsmouth. Available at: http://purl.stanford.edu/dx764wb2119 Gregory, I, Bennett, C, Gilham, V., and Southall, H. 2002. The Great Britain Historical GIS Project: from maps to changing human geography.' The Cartographic Journal, Vol. 39, No. 1, p. 37-49. Southall, H 2012, 'Rebuilding the Great Britain Historical GIS, part 2: a geo-spatial ontology of administrative units' Historical Methods: A Journal of Quantitative and Interdisciplinary History, vol 45, no. 3, pp. 119-134. DOI: 10.1080/01615440.2012.664101 For full details see License document included with this layer This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.