Hatfield is of Saxon origin. Hatfield House, home of the Marquess of Salisbury, is the most important country house. Aircraft were built from the 1930s when de Havilland opened a factory until the 1990s when British Aerospace closed it. Aircraft design and manufacture employed more people there than any other industry. Hatfield was one of the post-war New Towns built around London. It has modernist architecture from the period. The University of Hertfordshire is based there.
Hatfield is 20 miles (30 kilometres) north of London beside the A1(M) motorway and has direct trains to London King's Cross station, Finsbury Park and Moorgate. Commuters who work in London have moved into the area.