20 Facts About Joan Clarke

Joan Elisabeth Lowther Clarke was born on 24 June 1917 in West Norwood, London, England.

Joan Clarke was the youngest child of Dorothy and the Revd.

Joan Clarke gained a double first degree in mathematics and was a Wrangler.

Joan Clarke won the Philippa Fawcett prize and was awarded the Helen Gladstone scholarship for a further year of study.

Joan Clarke was denied a full degree, as until 1948 Cambridge awarded these only to men.

Joan Clarke arrived at Bletchley Park on 17 June 1940 and was initially placed in an all-women group, referred to as "The Girls", who mainly did routine clerical work.

Joan Clarke said she knew of only one other female cryptologist working at Bletchley Park.

Joan Clarke ended up working with Alan Turing at Bletchley Park in the section known as Hut 8 who she knew slightly through her older brother Michael.

Joan Clarke quickly became the only female practitioner of Banburismus, a cryptanalytic process developed by Alan Turing which reduced the need for bombes: electromechanical devices as used by British cryptologists Welchman and Turing to decipher German encrypted messages during World War II.

Joan Clarke had access to intercepted code papers and worked out that that same cipher was used on the fourth rotor as the three-rotor system, which enabled Shaun Wylie to break the code.

Joan Clarke and Turing had been close friends since soon after they met, and continued to be until Turing's death in 1954.

Joan Clarke later admitted that she suspected Turing's homosexuality for some time, and it was not much of a surprise when he made the admission to her.

Joan Clarke was awarded an MBE for her codebreaking activities in 1946.

Joan Clarke helped historians studying war-time codebreaking at Bletchley Park.

Joan Clarke established the sequence of the complex series of gold unicorn and heavy groat coins that were in circulation in Scotland during the reigns of James III and James IV.

Joan Clarke died at her home at 7 Larkfields, Headington Quarry on 4 September 1996 at age 79.

In May 2024 a blue plaque in Joan Clarke's memory was unveiled by English Heritage at 193 Rosendale Road, West Dulwich, London, SE21 8LW, her home as a child.

Joan Clarke was portrayed by Keira Knightley in the film The Imitation Game, opposite Benedict Cumberbatch as Alan Turing.

In contrast, an article by BBC journalist Joe Miller said that Joan Clarke's "story has been immortalised".

Director Morten Tyldum said the film shows how Joan Clarke succeeded in her field despite working in a time "when intelligence wasn't really appreciated in women".