Richard James Aldrich - GCHQ: the uncensored story of Britains most secret intelligence agency

For Libby (for the dark night-time)

1. Adastral Park, Martlesham Heath, Suffolk, BT Research Laboratories, 1975
2. Beaumanor/Garats Hay, Leic., postwar Army sigint base & Special Projects Agency, 194594
3. Bletchley Park; this remained a sigint training site after the war until 1985
4. Boddington, Glos, (RAF) military communications unit working with GCHQ
5. Bower, Bowermadden near Wick, listening station, closed 1975
6. Brawdy, Haverfordwest, Wales, 14 Signals Regiment (electronic warfare)
7. Brora, Sutherland, listening station, closed 1984
8. Capenhurst Tower, Cheshire, intercepting telephone traffic to Ireland, 199098
9. Cheadle, Staffs, (RAF) listening station, closed 1996
10. Cheltenham (Oakley and Benhall); GCHQ moved to the twin sites between 1952 and 1954
11. Chicksands, Beds, NSA/USAF until 1994, then UK Defence Intelligence & Security Centre
12. Cricklade, Wilts, GCHQ experimental radio station
13. Culmhead, Somerset, GCHQ Central Training School, replacing Bletchley, 198594
14. Digby, Lincs, main centre for RAF ground sigint and now UK joint services sigint centre
15. Edzell, Brechin, US Navy/NSA site, 196096
16. HMS Flowerdown, near Winchester, listening station, closed 1977
17. Gilnahirk, Belfast, listening station, closed 1978
18. Hanslope Park, near Milton Keynes, Diplomatic Wireless Service and DTMS
19. Hawklaw, (Cupar) Fife, listening station, closed 1988
20. Hereford, 264 Signal Squadron supporting 22 SAS
21. Irton Moor, Scarborough, listening station, now GCHQ Scarborough
22. Island Hill, Comber, Northern Ireland, closed 1977
23. Ivy Farm, Knockholt Pound, Kent, listening station
24. Kirknewton, near Edinburgh, US listening station, closed 1966
25. Menwith Hill, near Harrogate, US Army listening station, taken over by NSA 1963
26. HMS Mercury, near Petersfield, naval signals centre, 194193
27. Morwenstow, now GCHQ Bude, focused on satellite communications, 1969
28. Oakhanger, (RAF) control centre for Skynet since 1967
29. Royal Radar Establishment, Malvern, from 1953, later Defence Research Agency
30. Waddington, Lincs, (RAF) Nimrod R1s of 51 Squadron since 1995
31. Watton, Norfolk, (RAF) Central Signals Establishment, 192 Squadron 194563
32. Whaddon Manor, Bucks, outstation of Bletchley Park, closed 1946
33. Wyton, Cambridgeshire, (RAF) Comets and Nimrod R1s of 51 Squadron, 196395
34. London

Chester Road, Borehamwood, (GCHQ/SIS) factory making radio microphones in the 1950s

Chesterfield Street W1, London office for GCHQ in the late 1940s

Dollis Hill, North London, Post Office Research Station, 192175

Eastcote, Harrow; GCHQ moved here in 1946 and some comsec staff remained after 1952

Empress State Building, Earls Court, listening station, 196294

London Processing Group, St Dunstans Hill, City of London, moved to Cheltenham 1975

Northwood Hills, small postwar GCHQ site; Permanent Joint HQ since 1996

Palmer St W1, LCSA headquarters until 1969; also GCHQs London office

On 1 November 1919, Britain created the Government Code and Cypher School, or GC&CS, the nations first integrated code-making and code-breaking unit. The term GC&CS remained in widespread use until the end of the Second World War.

By contrast, Government Communications Headquarters, or GCHQ, is a term of uncertain origin. Originally developed as a cover name for Bletchley Park in late 1939, it competed for usage with several other designations, including BP, Station X and indeed GC&CS. However, the Government Code and Cypher School remained the formal title of the whole organisation in wartime. During 1946, GC&CS re-designated itself the London Signals Intelligence Centre when the staff of Bletchley Park decamped to a new site at Eastcote near Uxbridge, although GCHQ remained in widespread use as a cover name. On 1 November 1948, as Britains code-breakers began to investigate a further move away from London to Cheltenham, the term GCHQ was formally adopted and has remained in use ever since.

Code-breaker is also a troublesome phrase. Codes are usually considered to be words substituted for others, often chosen somewhat at random. Typically, the military operations that constituted D-Day in 1944 were code-named Overlord. By contrast, systems of communication where letters and numbers are substituted in an organised pattern, either by machine or by hand, are referred to as cyphers. Yet the term code-breaker is so frequently applied to the people who worked at Bletchley Park and at GCHQ that this book follows common usage.

The constantly changing names of the Soviet intelligence and security services are especially vexing and so, despite the inescapable anachronisms, the Soviet civilian intelligence service is referred to as KGB until 1989, while the military intelligence service is denoted as GRU. In Britain, the Security Service is denoted here by the commonly known term MI5 and its sister organisation, the Secret Intelligence Service or MI6, is referred to as SIS. Ships and submarines names are italicised, e.g. HMS Turpin. Onshore naval bases and training establishments, e.g. HMS Anderson, are not italicised.