The British government first used the site during the Second World War, constructing a military hospital in preparation for casualties from the D-Day landings.

As part of the Ministry of Defence's Project MoDEL, the site became surplus to military requirements and was sold in 2007 to be redeveloped for new housing.

[3] Bletchley Park established an outpost at the Eastcote site, known during the Second World War as HMS Pembroke V, to house some of the Bombe codebreaker machines used to decode German Enigma messages.

[5] A detachment of American personnel were stationed in a separate area, operating their own Bombe machines.

[6] At the end of the war in 1945, the Bombes were dismantled by the Wrens to be recycled, maintaining the secrecy of the operations.

[8] The operations at Bletchley Park under the name "Government Code and Cypher School" (GC&CS) moved to Eastcote on 1 April 1946.

[10] Six years later, in July 1952, GC&CS became "Government Communications Headquarters" (GCHQ) and began to move from Eastcote to new purpose-built buildings in Cheltenham.

A report by the London Borough of Hillingdon's planning department rejected the proposal in December that year on the grounds that the site was already overdeveloped.