Codebreaker
Anja requested her photo by www.facebook.com/TheElderwoodPhotography to be painted on her flight jacket. Although the painting shows herself the jacket is dedicated to the female codebreakers like Margaret Alice Rock.
After the outbreak of the Second World War, Margaret Alice Rock joined the services of the Government Code and Cypher School in 1940. From her new boss, the renowned codebreaker Dillwyn Knox, whom everyone called “Dilly”, she received the usual curt greeting, which also had to suffice as an introduction to her new task: “Hello, we’re breaking machines. Have you got a pencil? Here, have a go.” Together with Mavis Lever, who started at “Dilly” the same month as she did, and with whom she quickly became friends and remained friends throughout her life, she now worked on deciphering German radio messages encrypted with the Enigma. She was, like her colleague Mavis and Alan Turing’s co-worker Joan Clarke, one of the very few female codebreakers in B.P.
Her boss greatly appreciated the cooperation of his two capable female employees, who were highly respected in B.P. as “Dilly’s girls”, and praised them with the words “Give me a Lever and a Rock and I will move the Universe” as a play on words with the surnames of his two female employees.
On 8 December 1941, Margaret Rock made an important cryptanalytical breakthrough when, together with Mavis, she “cracked” for the first time a message encrypted by the German Abwehr (secret service) with the help of a special Enigma model (G). In this way, she made an important contribution to ensuring that German agents could be “received” as soon as they entered the country. These were not simply eliminated afterwards, but the British domestic intelligence service MI5 succeeded in “turning over” many of them and using them as double agents within the framework of the Double Cross system. Together with the information deciphered from Enigma G messages, MI5 obtained such a detailed and accurate picture of the plans and state of knowledge of the Abwehr that every single German agent still operating in Britain was precisely known and could be specifically controlled and manipulated. This was also used to disinform the German leadership (Operation Fortitude) and contributed significantly to the Allied success on D-Day, i.e. the successful landing of the Allies in Normandy (Operation Overlord).
In May 1943, Margaret achieved another important success when she succeeded in breaking into a radio line used by the Germans to transmit weather reports from weather ships near the Canary Islands, which were encoded with a special Enigma.
Margaret was awarded the Order of the British Empire (MBE) for her services in 1945. She remained with the G.C. & C.S., or its successor, Government Communications Headquarters (GCHQ) after the war until her retirement in July 1963. She was unmarried and later lived with her long-time friend, Norah Sheward, whom she knew from North Middlesex School. Margaret Rock died at the age of 80.
My painted interpretation of the photo
