Catalogue description Government Code and Cypher School: Diplomatic Section and predecessors: Decrypts of Intercepted Diplomatic Communications (BJ Series)

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Details of HW 12
Reference: HW 12
Title: Government Code and Cypher School: Diplomatic Section and predecessors: Decrypts of Intercepted Diplomatic Communications (BJ Series)
Description:

This series contains decrypted foreign diplomatic telegrams and reports by the Government Code and Cypher School. The origin of the series name 'BJ Reports' is that the reports were circulated by the Foreign Office (the main recipient) in blue file jackets. The records referred to as JUMBO reports are based on overseas interception (and often decryption), which could be received by telegraph or by courier from other authorities such as British forces in the Middle East, India and Hong Kong, which practised signals intelligence for their own purposes.. They forwarded material of high interest to London.

The material up to the end of 1925 covers such subjects as the Russian Civil War and subsequent Soviet negotiations for recognition; post-war settlements in Central and Eastern Europe; the occupation of Turkey and the Graeco-Turkish war; Great Power ambitions in the Middle East; Japanese ambitions in China and the Russian Far East; French intransigence on the questions of German reparations and European security; the rise to power of Mussolini and his increasingly aggressive political tactics to establish Italy as a Great Power.

1926 to 1929 covers Mussolini's growth in power and influence in the Balkans and Eastern Mediterranean and Italian aspirations in North and East Africa and Arabia; civil war in China and her attempts to throw off the control of foreign powers; civil war in Afghanistan and Russian penetration; the Kellogg Non-Aggression Pact and British, American and Japanese diplomatic consultations in preparation for the International Conference on Reduction of Naval Forces and related decrypts issued during the period of the conference from January to April 1930.

The years 1939-1945 are concerned almost exclusively with the conduct of the war.
Date: 1919-1945
Arrangement:

The volumes (one per month) are arranged in former reference order. Reports in each piece are listed by country. The first report issued on 19 October 1919 inaugurated a running series commencing at 000001. Serial numbers were allocated on the date of issue, the date of origination being given within the body of a report. A separate series (NC1-397) was used for Naval Conference related reports.

The time lapse between interception and reporting depended on the difficulty of the cipher involved, the current intelligence priority and where the message was obtained ("Jumbo" reports are based on overseas interception and often decryption, which could be received by telegraph or courier). In consideration of the usefulness of the intelligence, the date of issue is the more important.

Reports were issued in London and it is not known what arrangements, if any, were made to provide the intelligence to ministers and officials engaged in negotiations overseas, at Geneva and Lausanne for example. From HW 12/83 (1926 June) many reports are followed immediately by a special version (same serial number prefixed with 9). The purpose of these is not known, although they are written in a slightly different format, the addressees are similar. From 1926 August an index of report serials and titles occurs at the beginning of each piece.

For pieces HW 12/272-331 (covering the period 1942-August 1945), the items as listed in the catalogue descriptions were numbered arbitarily prior to accessioning. These numbers do not appear on the decrypts themselves.

Related material:

See also the Government Code and Cypher School: Signals Intelligence Passed to the Prime Minister, Messages and Correspondence in: HW 1
Separated material:

BJ volumes for June to December 1938 are missing.
Held by: The National Archives, Kew
Former reference in its original department: BJ file series
Legal status: Public Record(s)
Language: English
Creator:

Government Code and Cypher School, Diplomatic Section, 1919-1946
Physical description: 338 volume(s)
Access conditions: Subject to 30 year closure unless otherwise stated
Immediate source of acquisition:

In From 1996 Government Communications Headquarters
Accruals: Series is accruing
Unpublished finding aids:

An index to international questions referred to in the reports is available in the National Archives Kew. Please speak to staff at the enquiry desk for the precise location.

Administrative / biographical background:

Between 1918 and 1939, diplomatic intelligence was the main product of GC&CS, hence its transfer from Admiralty to Foreign Office control on 1922. The Diplomatic Section moved to Bletchley Park with the rest of the School in August 1939. Lack of space at the Park meant that the Section was soon relocated to Elmers School, but in early 1942 it returned to Berkeley Street, London to facilitate contact with the Foreign Office. Before the war, BJ reports were issued in London, and the exact means used to provide the intelligence to ministers and officials overseas , is now not known. During the war, arrangements were made for the secure disemmination of intelligence both at home and abroad (see for example HW 36, HW 37 and HW 39).

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