Women Codebreakers of World War I

EPOCH
10 hours ago
7 min read

Alison Sawers | University of Cambridge

An oil painting of a row of wooden huts, with barbed wire in the foreground. It is painted expressively in drab brown and green colours. There are some female figures visible in the distance. — The huts where the women codebreakers lived at the British headquarters at Saint-Omer, painted by ambulance driver Ernest Procter. (Credit: Ernest Procter via IWM (Art.IWM ART 3520); IWM Non-Commercial Licence).

In September 1917, Mabel Dymond Peel, a languages teacher who had joined the Women’s Army Auxiliary Corps (WAAC) to censor letters home from German prisoners of war, arrived near the front lines in France and was handed a coded message. ‘I think none of us will ever forget that first morning at the office,’ she said, ‘when we sat there [looking at] meaningless groups of letters… Never having 'seen a code message in our lives before, you can imagine the despair that filled our hearts’.

Mabel was among the first cohort of women codebreakers of World War I. Recently, the contributions of women codebreakers in World War II, especially at Bletchley Park, have been increasingly brought to light through books, exhibitions, and the BBC drama The Bletchley Circle (2012–14). Before that, though, codebreaking was also an area where women contributed during World War I, in the so-called ‘Hush WAACs’ and a branch of British Military Intelligence set up at this time for the purpose of cryptanalysis – MI1(b).

Mabel and her five colleagues, the secretive Hush WAACs, had been selected for their knowledge of German - even if it were a ‘somewhat rusty’ knowledge, according to the youngest of the group, 22-year-old Gwendoline Watkins. By 1916, the British Army was running out of manpower on the front lines and decided to free up more men by employing women in support roles such as administration, catering, and censorship, as Mabel had been doing. In 1917, women who spoke German were also selected to support the work of codebreakers at the British Expeditionary Force headquarters at Saint-Omer, France. They had not been told what kind of work they were going to do.

However, Mabel was no stranger to adventure – or to France. At the age of 19, she had taken herself off to the south of France as a freelance teacher of French and the violin. Her brother and sister had also joined the war effort before her. Mabel and her colleagues rose to the challenge: ‘We began to find our work intensely interesting, and as we began to see more and more daylight in it, found it monopolising all our thoughts both waking and sleeping,’ she said in her memoir. ‘At the end of three months, a colleague and myself decoded our daily messages quite by ourselves’.

Conditions at Saint-Omer were not safe or pleasant, with wooden huts to live in and night-time bombing raids. Gwendoline recalled ‘paddling about’ when the camp became a cold, wet swamp in winter, and telling a new recruit in ‘frigidly anti-hysterical tones’ that they remained in their huts when there was an air raid. They worked until 10pm every day of the week, their first day off coming seven months into their stint. After Mabel and Gwendoline’s group, the ‘Secret Six’, were first sent out, there followed a group called the ‘Three Mutineers’, who objected to the living conditions and immediately returned home.

For other women, the thrill of the work was enough for them to stay. They solved the codes with the help of codebooks taken from captured German soldiers, which Gwendoline said they gave personal names like Adolph and Gretchen. On one occasion, they also used an intercepted message which was accidentally transmitted in both old and new codes, giving the cryptanalysts an insight into the new cyphers. The women sometimes rose to take charge of their respective rooms, and other times were relegated to more monotonous tasks. Mabel contributed to a catalogue of common phrases which could be used to help break codes by analysing their context. In total, at least seventeen women worked as Hush WAACs in 1917–18, including Florence Hannam and Mary Tiltman, whose younger brother John Tiltman was to become a codebreaker himself at Bletchley Park.

A black and white photograph of two women in WAAC uniform, including long coats and hats, carrying German helmets filled with tins of food. The woman on the left is grinning at her companion, who smiles at the camera. — Members of the WAAC at the Hush WAACs’ second headquarters at Étaples, carrying ration tins in German helmets. They were photographed by 2nd Lieutenant David Lellan in April 1918. (Credit: David McLellan via IWM (Q 8744); IWM Non Commercial Licence).

Mabel remained in France until the end of the war, following the headquarters to a new base when Saint-Omer became too dangerous during the German spring offensive of 1918, with the Germans advancing to within fifteen miles of the camp. She was finally recalled in December, after the armistice, and was awarded the Victory Medal and the War Medal for her service. Mabel’s connections with France and with the armed forces were to continue: she spent the post-war years in Rouen, where she set up a branch of the British Legion to help support unemployed ex-servicemen. Her 1921 memoir, The Story of the Hush-WAACs, helped keep her and her colleagues’ experiences from being lost.

A close-up of a World War I Victory medal. It has a rainbow-coloured ribbon and a bronze medallion which reads 'The Great War for Civilisation 1914–1919'. — Several Hush WAACs, including Mabel Peel, Gwendoline Watkins and Florence Hannam, received the Victory Medal and the British War Medal for their service. (Credit: Aukland Museum; CC BY 4.0).

After their stints on the frontline, some of the Hush WAACs – Gwendoline and Florence Hannam – continued their codebreaking work at MI1(b). Unlike its Admiralty equivalent, Room 40, which employed women in clerical roles, MI1(b) had women codebreakers. They worked on codes of French, German, Italian, Spanish, Uruguayan, and Argentine origins, and even, in the case of Gwendoline and Florence, on ‘non-alphabetical Romanian field codes’. In fact, in 1919, women accounted for a third of MI1(b)’s civilian cryptanalysts and linguists.

These women were university-educated, and many of them were lecturers or language teachers in schools, such as Alda Milner-Barry, who had been teaching modern languages at the University of Bangor while she was still a 21-year-old student at Cambridge. Other codebreakers had been using their language skills for other purposes. Florence Hayllar, a 50-year-old poet and novelist, loved a good language puzzle: she was editor of the linguistics journal Notes & Queries for thirty years. Barbara Freire-Marreco was a well-known anthropologist who had done fieldwork in the pueblos of New Mexico, where she had helped the indigenous Yavapai and Tewa-speaking people with legal proceedings to claim their rights from the US government.

As with the Hush WAACs, selecting women to work at MI1(b) was at first done via personal contact on the basis of linguistic ability. In 1917, MI1(b) moved to new premises on Cork Street for its expanded workforce, and its head, Major Malcolm Hay, wanted to professionalise the recruitment process so as to filter out the strongest candidates for his ‘Cork Street Code Breakers’. He came up with a test he thought ‘practically impossible’, and the only candidate who was able to solve it was a school headmistress and children’s writer with a love of Norse mythology and amateur dramatics: Claribel Spurling.

Major Hay was not famed for respecting the talents of women – he dismissively referred to one woman candidate as ‘good at pouring the tea’ – but Claribel caught his attention: ‘Miss Spurling’s imagination and tenacity were remarkable,’ he said. When war broke out, she had originally intended to travel to Canada but was unable to get the paperwork for it. In 1917, after her brother was killed in action, she joined the Women’s Royal Naval Service instead. She worked on French, German, and Italian codes with MI1(b), but Hay’s enthusiasm for her was not reciprocated. She wrote a spoof poem about the excessive attention he paid to his female employees:

Our names, weights, ages, heights & sex,

The way we do our hair,

Which tongues we talk, what ways we walk,

Were objects of his care.

The lines suggest that some men were still getting used to the wartime development of working alongside women as colleagues in professional roles.

After the war, Claribel, Gwendoline, both the Florences, and some of their colleagues went on to work at the Government Code and Cypher School (GC&CS), which was set up in 1919 to continue intelligence work during peacetime. They were appointed to the position of Junior Assistant, with Claribel being the first woman to attain this rank.

Many of the Cork Street Code Breakers remained at GC&CS for only a few months before going on to pursue their other passions. Claribel became one of the first women to receive a degree from the University of Oxford – having studied there in the 1890s, she was finally granted an MA when Oxford began awarding degrees to women in 1920. She continued to bring her ‘imagination and tenacity’ to her future roles as a university warden, and set up an international club for university women, as well as continuing her writing adapting medieval legends for children. Florence Hayllar went back to her writing and editing, and the precocious Alda Milner-Barry became vice-principal of Newnham College, Cambridge, from where she recruited women students to work at Bletchley Park. Barbara Freire-Marreco married one of her colleagues in the War Intelligence Department and retired.

One of the women, however – Emily Anderson, an Irish suffragette who had studied in Germany, taught in Barbados, and originally trained as a Hush WAAC before taking up a post at MI1(b) instead of going to the front lines – remained at GC&CS for almost thirty years. Alongside her research as a musicologist, her codebreaking career culminated in receiving an OBE for her World War II intelligence work, including working at Bletchley Park and deciphering crucial messages for the North African front from her base in Cairo. She became known as the best woman codebreaker of the twentieth century – and, having stipulated that her pay must be equal to that of her male colleagues, certainly the best-paid.

Information about these women codebreakers is not always easy to come by. Apart from Mabel and Gwendoline, we do not hear the voices of the rest of the Secret Six Hush WAACs: Catherine Osborne, Aline Robertson, Elsie Thring, and their beloved Unit Administrator, Mary Boord. Likewise, there is little information we can attach to the names of the WAACs who joined afterwards: Olivia Chevallier, Dorothy Deighton, Florence Hannam, Dorothy Jackson, Katherine Masters, Gladys and Violet Munby, Nora Skelton, and Mary Tiltman. Miss J.F. Carleton, Miss Chichester, and the other nameless women who made up MI1(b)’s female personnel are even more elusive. Some records were deliberately destroyed to maintain the secrecy of organisations like MI1(b). Additionally, awareness of women’s contributions to this field may have suffered due to historiographical biases of wartime accounts and the attitudes of men in authority, such as Major Hay. However, some writers are now working to fulfil the wish expressed in a poem by Florence Hayllar at Major Hay’s going-away party in 1919, called ‘The Shade of MI1(b) and Its Chief’:

[To], by the gracious Art of Memory,

Lend yet a Form, a shadowy Entity,

To that which we once were – MI1(b).