The early 20th century, but especially the period between the two wars, saw the geographical extent of London's urban area grow faster than at any point before or since. Most of the development was suburban into the neighbouring counties of Essex, Hertfordshire, Kent, Middlesex and Surrey.
People were encouraged to move out from the overcrowded centre of London to lower density suburban housing. The Government of the day also wanted to build 'Homes for Heroes', for soldiers returning from the war. It granted subsidies to encourage house-building. During this period of unprecedented development many semi detached homes were built and developers marketed them as offering a more rural, tranquil lifestyle.
The rapid development across London during this period swallowed up large swathes of countryside. Eventually, fears over the scale of this loss eventually led to the passing of the Green Belt Act 1938, which restricted, and continues to restrict, urban growth to this day.
All this development meant that London outgrew the boundaries of the County of London, which led to calls by the London County Council (LCC) for the creation of a single Greater London Authority covering the entire urban area. This was rejected by a Royal Commission in 1921, partly due to protests about areas such as Eton, Windsor and Slough being included in an enlarged authority, and it was not until 1965 that the Greater London Council (GLC) was finally created.
The rapid growth of London during this period was facilitated by prompt expansion and modernisation of its transport networks. Even from 1900, London had motorised buses and trams. Large scale electrification of London's commuter railways also took place during the interwar period and the London Underground was expanded to London's northern outer suburbs. Even the road network was modernised with a structure of arterial roads being constructed in the 1920s and 30s, including the A406 North Circular Road.
The population of London's urban area reached its all time peak of about 8.6 million in 1939. All of this growth occurred outside of the boundaries of the County of London.Next page: London's Economy 1900 - 1939