Explore the county boundaries of Great Britain throughout time with our counties map.
These two datasets of county boundary information have been released as part of Boundary-Line through the popular OS OpenData portal.
OS has been mapping the changing physical landscape of Great Britain for the past 224 years. It is not only the landscape which has changed, but our county boundaries have also changed over the past two centuries.
These datasets have been created as part of a project with the Department of Communities and Local Government (DCLG). The current and historic county boundaries have been added to our administrative boundary data under the open data portfolio.
Counties defined by the Local Government Act 1972 and used for administrative purposes.
Ceremonial counties, as defined by the Lieutenancies Act 1997, refer to the areas relating to the Lord-lieutenants, the monarch’s representatives. Historic counties are geographical boundaries that date back over many centuries