The satellite garden city, as an urbanization process, was invented and tested in England at the beginning of the twentieth century. Whatever the genesis and the context of its production, this process of urbanization first appeared theoretically in 1898 with the publication by Ebenezer Howard of Tomorrow: A Peaceful Path to Real Reform. From this date onward, it is easy to set out the history of the evolution of this process according to some specific dates:

1904: Letchworth, the first garden city built according to the economic development model of Howard and the first important realization by Raymond Unwin and Barry Parker; 1909: Hampstead, the first garden suburb built according to the design ideas of Unwin; 1919: Welwyn, the first garden city that combined in the same project the theories of Howard and the practical methods of Unwin;

If we have not chosen to discuss Letchworth, it is because Welwyn showed the same means of production while profiting from the experiences of its older sister.