The de Havilland company, who were based in nearby Hatfield, entered into a contract with the Air Ministry to produce what would become known as the Mosquito fast bomber aircraft.

Space for the large scale hangars needed to produce the huge number of aeroplanes required was not available at de Havilland's Hatfield Aerodrome, so the Ministry of Supply requisitioned this new site in Leavesden, which was an empty plot of land at the time from the Watford Corporation, and it was developed into the complex that it is today.

After the war, the aerodrome was purchased outright by de Havilland, who themselves had a succession of owners in the following decades, including Hawker Siddeley from 1959, but ultimately they and the site were acquired by Rolls-Royce who continued production and design of helicopter engines.

Under Rolls-Royce ownership the RTM322 engine for the UK Apache, Merlin and NH90 helicopters was designed, developed and produced at Leavesden as a joint venture with Turbomeca of France.

However, by the early 1990s, Britain's manufacturing industry was in decline and Rolls-Royce had sold their interests in the site and transferred all work to their Bristol facility.

Facing little time to find a space in which they could build the number of large scale sets required, the production discovered the unoccupied Leavesden.

Eon leased the site for the duration of their shoot and went about gutting the factories, turning them into the stages, workshops and offices needed for a working film studio.

Members of the production crew, impressed by the enormous size of the filmmaking complex they suddenly had to themselves, jokingly called Leavesden "Cubbywood" after Eon's long serving producer Albert R. 'Cubby' Broccoli.

A succession of major feature films made use of the site; in 1997, the first of the Star Wars prequels, The Phantom Menace, and later Tim Burton's Sleepy Hollow.

One of the more noticeable exterior sets constructed on the Leavesden backlot (outdoors) was a row of ten houses (five per side) along a street, which was created for the Harry Potter series to represent Privet Drive.

The full scale refurbishment and renovation of the production facilities were completed and the studios reopened to film and television work in 2012.

On 30 June 2014, Warner Bros. announced the expansion of the studio, building three new state-of-the-art stages and adding a further 10,000 m2 (110,000 sq ft) of office space.

[21] On their visit, they were accompanied by the Duke's brother Prince Harry and J. K. Rowling (who had been unable to attend the tour's grand opening the year before), amongst other guests.

The royal entourage visited both the tour and the studios, viewing the props and costumes from Christopher Nolan's Batman films, before conducting the site's inauguration.

Sets like the Great Hall, Dumbledore's Office, Diagon Alley, the Ministry of Magic, Gryffindor Common Room and Boys' Dormitory, Hagrid's Hut and a 1:24 scale model of Hogwarts Castle.

[citation needed] Warner Bros. has continued to put on special features following a seasonal rotation, such as Dark Arts, Magical mischief and Hogwarts in the snow.

[39] In January 2015, the attraction's first expansion was announced – a new Platform 9¾ section, where visitors are able to board the original carriages behind the Hogwarts Express steam engine used in the films.

The setup includes the locomotive GWR 4900 Class 5972 Olton Hall (dressed as 5972 Hogwarts Express) and the British Rail Mark 1 train that appeared in the films, brought to life by John Richardson's special effects team.