Government Code and Cypher School: Diplomatic Section and predecessors: Decrypts...

HW 12

1919-1945

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.

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.

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

BJ volumes for June to December 1938 are missing.

BJ file series

Public Record(s)

English

338 volume(s)

Subject to 30 year closure unless otherwise stated

In From 1996 Government Communications Headquarters

Topics

International

Asia

Treaties and alliances

Europe and Russia

Conflict

Intelligence

Navy

Middle East

Communications

Armed Forces (General Administration)

Operations, battles and campaigns

Africa

Series is accruing

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).