How codebreakers helped fight the Battle of Britain

Last Updated: 14 Sep 2016
Analysts at GCHQ's forerunner Bletchley Park provided vital intelligence in the struggle to defend Britain's skies.

The first major breakthrough in the regular decryption of German traffic during World War II was the reading of Luftwaffe messages from the spring of 1940 onwards.

The Germans used Enigma, as well as other lower-grade encryption systems, and analysts at Bletchley Park and RAF Cheadle were increasingly able throughout the Battle of Britain to give indicators and warnings to Fighter Command to allow it to target its scant resources against the German Air Force.

Understanding the German directional beam system took longer, and the contribution of radar and photographic intelligence during the Battle of Britain should also be celebrated.

We at GCHQ are proud to be the successors of the women and men who helped give the RAF the information advantage they needed to help halt the Luftwaffe.


Battle of Britain air observer
©National Archives and Records Administration (541899)