London overspill communities were established as part of a government-led initiative to alleviate overcrowding in Greater London by relocating residents to other parts of England between the 1930s and 1970s. The earliest efforts focused on nearby areas in the South East, with the development of towns such as Harlow, Crawley, Basildon, and Stevenage. These initiatives were underpinned by the Greater London Plan of 1944, authored by Patrick Abercrombie, which proposed a ring of satellite towns beyond a newly defined Green Belt to decentralise population and industry.
From the 1950s, the scheme extended into East Anglia, where towns such as King's Lynn, Thetford, Haverhill, and Bury St Edmunds were expanded or redeveloped to accommodate Londoners. This regional inclusion aligned with the New Towns Act of 1946, which empowered the government to designate development areas and establish corporations to oversee their planning and growth. Peterborough, for instance, was designated a New Town in 1967 with a target population increase of 70,000.
