Joan Clarke may be a familiar name to you soon. She is featured alongside Alan Turing in the film “The Imitation Game”. The film details the code breaking of German communications at Bletchley Park during World War II. Benedict Cumberbatch plays Alan Turing and Keira Knightley plays Joan Clarke. The movie won’t be in my area until December 24th. Alas!

In the meantime, I’ve researched Joan Clarke on my own to learn about the woman that was once upon a time engaged to Alan Turing.


Joan Clarke – Image via Wikipedia

Joan Clarke, born June 24th, 1917, was born the youngest child. She had three older brothers and one older sister. After graduating high school in 1936, Joan entered Newnham College in Cambridge to study mathematics. In 1939 she completed two of the three parts of her mathematics degree. She finished part three of her degree in 1940 but it was only an honorary title. Full degrees were not given to women until after the war.

Decoding was needed during the war as German communications were encrypted by an Enigma machine. The machine had rotating wheels and rotors that scrambled messages. The settings on the Enigma were changed every day thus making the code seem unbreakable. The odds of deciphering a message were an extraordinary 150 million million million to one.

Joan was brought on to the Enigma decoding operation via Gordon Welchman. Joan was a classmate of his and he was highly impressed with her mathematical ability. She started doing clerical work at Bletchley Park along with a large group of women called “the girls” in the section known as Hut 8. The ratio of women to men was 8:1.

Image via Wikipedia

Bletchley Park – Image via Wikipedia

A linguist position was engineered for her to provide a pay raise in recognition for her hard work. Clarke struggled to be promoted further. She felt it was due to her sex. Events would turn in Clarke’s favor as Turing created a new code breaking process known as Banburismus. Banburismus decreased the possible combinations that the Enigma wheels could make. Clarke was the only female on the team.

Clarke and Turing began arranging their work schedules so they could have the same shifts off to spend more time together. In the spring of 1941, Turing proposed to Clarke. The engagement had its trials as Turing later admitted his homosexual tendencies. Clarke was unfazed by his confession and kept the engagement going until late that summer when the engagement was mutually called off. Turing felt that the marriage would fail due to his homosexuality.

The team continued to work on the Enigma until the war ended in the spring of 1945. By the spring of 1946, all of the workers were gone and all of the evidence of the secret code breaking was disposed of. A year later, Joan was appointed a Member of the British Empire (MBE) for her code breaking work.

Even though the war had ended, code breaking did continue. Clarke met Lieutenant-Colonel Murray, a retired army officer. The two married in 1952. They did not have any children.

Joan retired at age 60 and began to research numismatics; the study and collection of coins, paper money and medals. She excelled at this as well. In 1987, Joan received the Sandford Saltus Medal by the British Numismatic Society for her contribution to numismatics.

In September of 1996, Joan passed quietly at home. Much of her work is still unknown due to the Official Secrets Act. Nevertheless, Joan Clarke’s contribution to Enigma code breaking has saved many lives.

I hope after reading this you are as excited to see “The Imitation Game” as I am!

References:  1, 2