Bletchley Park - post-war

Last Updated: 01 Apr 2016
After World War II, the Government Code & Cypher School changed its name officially to GCHQ and moved its headquarters to Eastcote, Middlesex in 1946, and then to Cheltenham in the 1950s. The Central Training School stayed at Bletchley Park until 1987, when it moved to Culmhead, near Taunton in Somerset.   

The entire Bletchley Park site, apart from the Listed mansion, including all the wartime Government Code & Cypher School (GC&CS) buildings, was in danger of being sold for development after the end of World War II. However, a group of enthusiasts set up the Bletchley Park Trust which saved the central part of the site. This has developed into a major heritage site commemorating the work done at Bletchley Park during the war.

GCHQ has supported Trust-sponsored construction of working replicas of both COLOSSUS and a Bombe, and is supporting work on the building of a reconstruction of DELILAH, a post-war secure speech system.  

The Bletchley Park Trust preserves part of the history of British Sigint. GCHQ supports the Trust by providing significant numbers of artefacts and documents for display. Members of staff new to GCHQ visit Bletchley Park as part of their induction process to learn something of the skills and values of our predecessors. The innovative and inspiring work of Bletchley Park remains an inspiration to all who work in Intelligence. 

GCHQ Post War

From VJ Day 1945 until the collapse of the Warsaw Pact in 1991, the dominant military threat to the United Kingdom was the armed forces of the Soviet Bloc. These were therefore the main focus of GCHQ's Sigint efforts, while CESG was responsible for developing defensive systems to protect UK government communications against foreign Sigint services. Since November 2007, GCHQ has been releasing copies of its intelligence reports on Soviet Bloc military and paramilitary activities up to 1950 to The National Archives at Kew.

 Since 1946, GCHQ has always provided intelligence and Information Assurance support to military, diplomatic and law enforcement Departments of the UK Government and its Allies.  

One of the enduring legacies of World War II is the Sigint relationship between the UK and the US, to which the Sigint agencies of Canada, Australia and New Zealand have also signed up. Details of the UKUSA Agreement and its development were released to the National Archives in 2009.​


C Block Oakley