In a book written in the 5th Century BCE, a famous Chinese military leader, Sun Tzu, devoted a whole chapter to “The Use of Spies”. He reached the conclusion that “what enables the wise sovereign and the good general to strike and conquer, and achieve things beyond the reach of ordinary men, is foreknowledge”. Between 1914 and 1918, both sides did their uttermost to recruit, train and use spies to gather that ‘foreknowledge’. Although men were sent close to the battle fronts, women worked behind the lines on both sides. Spies’ watchful eyes and listening ears provided both sides with intelligence about what was going on behind the scenes.  

Elisabeth Schragmüller - AKA Fraulein Doktor (1887-1940)


Code-named Fraulein Doktor, in August 1914, like thousands of women on all sides, Elisabeth was desperate to ‘do her bit’ for Germany’s war effort. To begin with, Germany wasn’t convinced Elisabeth could be useful but eventually the military authorities sent her to Antwerp in German-Occupied Belgium. Elisabeth was tasked with the important job of recruiting and training spies to be sent throughout France. Elisabeth organised a spy school to teach recruits these skills and how to develop secret codes, create invisible ink and miniature handwriting. Messages were hidden in accessories such as umbrellas, in shoe heels, hollowed-out vegetables, rolled into tiny packages or enclosed in small pieces of inflammable materials stuffed inside a cigar or cigarette. If someone dangerous approached they just lit up and puffed away!

Elisabeth didn’t care if her spies were men or women, all that mattered was their ability and found excellent spies in unlikely places. One of her best was a florist who couldn’t read or write but was brilliant at remembering what he had seen, he had a ‘photographic memory’. It has been estimated that Elisabeth sent over 100 female agents into France (20 were caught) and at least four times as many men. 

Martha Cnockaert (1892 – 1966)

During the summer of 1914 Martha was training to be a doctor, and so after Germany invaded Belgium she was conscripted to work as a nurse at a German Military Hospital near her home in Roulers, Belgium.



A British spy master approached Martha to be a spy to which she agreed out of a sense of loyalty to Belgium. She was told to gather information about troop movements around Roulers station, an important railhead for the Germans. In spring 1915, thanks to her information, the Allies bombed the station.

Martha describes how she had “wandered along an endless street of smoking ruins where the way was strewn with mangled corpses whose glassy eyeballs watched me accusingly.”    

On 22nd April 1915, both German and Allied casualties of the first gas attack flooded in to her hospital. No-one knew how to help these poor gassed men but she worked round the clock doing whatever she could. Martha’s dedication earned her the German Iron Cross which was presented to her by the King of Würtemburg.

The Germans then asked Martha to spy for them but she refused. She fell into a trap they set. In November 1916, she was arrested. The court found her guilty of espionage and she was sentenced to death. Roulers Military Hospital’s Chief Doctor spoke out in her defence. Her sentence was changed to life imprisonment.  

After the war, Martha was mentioned in British General Sir Douglas Haig’s Dispatches. The French and the Belgian Légions d’Honneur followed, making her the only person to have been decorated by four of the main combatants of the Great War.  

Louise de Bettignies (1880-1918)

Born in Lille, France, Louise was exceptionally clever and spoke five languages fluently, including English. When the Germans captured Lille in October 1914 the British recruited her to spy for them in Occupied France. At an English spy school, she learnt how to create miniature maps, write in invisible ink on tissue paper, engrave minute letters on spectacle frames, conceal messages in shoe heels, umbrella handles, hems of skirts and hollowed out vegetables. 

She used her map-drawing skills to create a miniature map of the German lines showing two thousand gun positions.  The Germans called the forty kilometres where her networks operated the "cursed" front; this was where they seemed to suffer the greatest number of unexpected attacks and aerial bombardments.  

Sadly, her information was sometimes ignored.  When Louise reported that the Germans were preparing a massive attack on Verdun in early 1916, the French commander discounted it – the information came from a woman.  The Battle of Verdun resulted in 262,308 French and German dead or missing.

Louise was arrested in autumn 1915 and went to trial the following March. The Germans sentenced Louise to life imprisonment with hard labour. During the winter of 1917 Louise developed pleurisy and died on 27th September 1918, 45 days before the Armistice.

She had been mentioned in Marsh Joffre’s dispatches in April 1916 and was awarded the French Légion d’Honneur, the Croix de guerre 1914-1918 with palm, the British Military Medal and the OBE.

In November 1927, a monument to Louise de Betignies and the ‘heroic women’ of the
Occupied Territories was unveiled.

Gabrielle Petit (1893 – 1916)



Gabrielle Petit, a local 21-year-old shop assistant in Brussels was furious when Germany had occupied on 20th August 1914. She wanted to share her knowledge of the surrounding area and activities of the Germans with the British. In July 1915 shewas invited by the British authorities to London’s Spy School.

Back in Brussels, she soon created her own spy network. She crossed backwards and forwards between Occupied France and Belgium carrying TOP SECRET information and she was always on the look-out for anything the Allies might find useful.

Gabrielle was arrested on 20th January 1916 and thrown into St Gilles Prison, Brussels. At every interrogation she stressed her loathing of the Germans. After a trial conducted in German, she only spoke French, and without knowing anyone influential to plead on her behalf, Gabrielle was sentenced to ‘Death by Firing Squad’

After the war, combatant nations sought to memorialise their glorious dead. In Belgium someone thought of the little Brussels shop assistant, Gabrielle would become Belgium’s martyr. In May 1919, her body was
exhumed; at an elaborate funeral the Belgian queen awarded Gabrielle the Croix de l’Ordre de Léopold.
Gabrielle’s statue still stands in Brussels’ Place St Jean. She looks down proudly on passers-by and reminds them that poor and young though she was, Gabrielle Petit had known both how to spy and how to die for her beloved Belgium.



Some students could write up to 1,600 words on a postage stamp to send secret message.