GCHQ has revealed for the first time the location that was its London base.
The Intelligence, Cyber and Security Agency, which also has a base in Scarborough, has revealed it has been operating unknown to the public for more than 66 years from a previously secret location tucked away on a busy London street opposite St James’ Park tube station in Westminster.
GCHQ, which uses cutting-edge technology and technical ingenuity to identify and disrupt threats to the UK, has moved out of the building, and so is able to reveal the role it has played in keeping the UK safe.
The agency's director, Jeremy Fleming said: “As we depart our Palmer Street site after 66 years, we look back on a history full of amazing intelligence, world-leading innovation, and the ingenious people who passed through those secret doors.
"Then, as now, it’s a history defined by the belief that with the right mix of minds, anything is possible.”
Today’s revelation is possible as GCHQ, whilst maintaining a London presence, will no longer operate from the building.
It comes as the organisation looks to further extend its network of sites in the UK, with a new secure facility in Manchester opening later this year, bringing hundreds of jobs to the region.
As well as its headquarters in Cheltenham and the site on Racecourse Road in Scarborough, the agency also has offices in Bude in Cornwall, Lincolnshire and Harrogate.
In 2017, the National Cyber Security Centre (NCSC), which is part of GCHQ, opened its new headquarters near Victoria in London and earlier this year, the Queen, commemorated the agency's 100-year anniversary by unveiling an historic plaque at a different London site – Watergate House, the first home and birthplace of the organisation.
GCHQ, or the Government Code & Cypher School (GC&CS) as it was known at the time, was established on 1 November 1919 as a peacetime cryptanalytic unit.
During World War Two staff moved to Bletchley Park where they decrypted German messages, most famously by breaking Enigma-encrypted communications, making a significant contribution to the Allied victory.
In the early 1950s, GCHQ moved its headquarters from the London suburbs of Eastcote to Cheltenham, meaning a suitable central London location was needed for the handling of secret paperwork and as a regular base for the Director.
After a substantial search, the Ministry of Works provided a newly-built, Government leased building on Palmer Street.
GCHQ moved into their new, secret London home in Spring 1953, housing a range of different teams there over the following decades.