Old Hatfield, was focussed around Hatfield House and its estate and land holdings and the town was largely agricultural. With the coming of the railway in the mid 19th century there was a gradual movement westwards until 1934 when the Barnet-by-pass had been completed. The railway had been the town’s biggest employer, but it had started to fade in the 1920s.
In 1934, de Havilland Aircraft Company came to Hatfield, and quickly took over as the town’s biggest employer, later taken over by Hawker Siddeley and BAe. The vast majority of de Havilland employees lived in Hatfield. House building began in earnest for its workers i.e. Ellenbrook, Hatfield Garden Village, St. Albans Road West and Birchwood.
Expansion increased after the Second World War when Hatfield was included in the nationwide development of new towns. It was chosen as a new town in partnership with nearby Welwyn Garden City in 1948. The population of Hatfield in 1934 had been 4,500 whilst in 1954 it had risen to 25,000. Hatfield new town began to be built in South Hatfield in 1951, with many of the new houses going to de Havilland employees. Hatfield was largely dependent on de Havilland and its successors for its prosperity.
