General records of the Government Code and Cypher School (GCCS) and Government Communications Headquarters (GCHQ) relating to responsibilities for intercepting enemy communications, particularly during the Second World War, and for ensuring security of the government's electronic communications. Consists of:
SENIOR MANAGEMENT PAPERS: Daily correspondence between Prime Minister and Director of GCCS HW 1, HW 71; Second World War intelligence summaries HW 13 and policy papers HW 14; Signals intelligence forwarded to allied commands, Tactical HW 20 and Political HW 39; Directorate and senior committee HW 42; Second World War in the Far East, summary reports HW 44; Air Section HW 56; Y Board and Sigint Board HW 69.
SOVIET COMMUNICATIONS: Venona Project HW 15; Decrypts of Communist International intercepts HW 17.
JAPANESE MILITARY COMMUNICATIONS: Japanese naval decrypts HW 23, naval air decrypts HW 27, army airforce decrypts HW 28, army decrypts HW 33, military attachees decrypts HW 34, and military intelligence decrypts HW 46; Japanese Section correspondence and earlier papers on Japanese matters HW 67.
HISTORIES AND PERSONAL PAPERS: Personal papers, unofficial histories, miscellaneous records, 1914-1945 HW 3; Official war histories for the two World Wars written by GCCS staff HW 7, HW 11; Histories of work at Bletchley Park HW 25, HW 43; Special Liaison Units histories HW 49; Papers on writing of the history of British signals intelligence HW 50; Papers relating to comsec editing of Winston Churchill's 'The Second World War' HW 72.
GERMAN MILITARY COMMUNICATIONS: German Section decrypts of German armed forces signals and of German and Italian intelligence services signals from 1940, German police messages and German Secret Service messages HW 5, HW 16, HW 19, HW 45; Naval Section reports of German, Italian, French, Spanish and Portuguese naval decrypts HW 18; German plans for sea-born invasion of Britain HW 48; Hut 6 and Hut 8 weekly reports HW 77.
BULGARIAN, CROATIAN, FRENCH, IRANIAN, ITALIAN PORTUGUESE AND SPANISH COMMUNICATIONS: Air Section reports on Italian and other foreign air forces HW 21; Naval, Air and Military Sections reports of Spanish military and civilian activity HW 22; Decrypts of Bulgarian military attache messages HW 24; Army section reports on Croatian military and naval activity HW 26; Intercepts of Iranian communications HW 58; Reports of Bulgarian Danube river and naval port authority decrypts HW 70.
DIPLOMATIC, COMMERCIAL AND METEOROLOGICAL COMMUNICATIONS: Japanese Section summary reports from intercepted Japanese and Siamese diplomatic communications HW 10, HW 38; Diplomatic intercept decrypts HW 12, HW 37; Commercial Section HW 29; Japanese Commercial HW 30; Diplomatic and Commercial Section HW 32; German diplomatic communications HW 36; Diplomatic and Commercial Sections HW 53; Intercepts of meteorological reports HW 54.
LIAISON WITH ALLIED ORGANISATIONS: Polish business and activities files HW 47; US based intelligence organisations HW 57; Intelligence related allied cypher messages HW 74.
COMMUNICATIONS SECURITY: Radio security service HW 35; Communications security HW 40; German signals intelligence Second World War HW 73.
FIELD SIGNALS INTELLIGENCE: Field signals intelligence HW 41; Middle East and North Africa HW 68.
TECHNICAL MATTERS: 'Y' Station HW 55; Air Section HW 66.
INTERCEPTED PLAIN LANGUAGE COMMUNICATIONS: Reports of plain language code HW 29.
WIRELESS TELEGRAPH SECTION: Coordinator Section records HW 63.
GC&CS ADMINISTRATION: Establishments records HW 64.
RESEARCH SECTION: Weekly reports, memoranda and minutes HW 78.