[3] Her exploits during the war included destroying a telephone line which a local priest was using to spy for the Germans; and obtaining details of a planned but cancelled visit by Kaiser Wilhelm II for a British aerial attack.
Cnockaert attempted to relay harmless but seemingly important information to him for a short time, but when operating as a double agent became too difficult, she arranged for him to be killed.
[5] Cnockaert was awarded British, French and Belgian honours for gallantry for her espionage work—she was mentioned in despatches on 8 November 1918 by Field Marshal Sir Douglas Haig in recognition of her intelligence work, as well as receiving a British certificate for gallantry from Winston Churchill; she was also made a member of the French and Belgian Legions of Honour.
[5] The publication of her memoir was prompted by the visit of an English author who encouraged Marthe to write and publish details of her wartime experiences.
Following a warm critical and popular reception of her memoirs and other espionage anecdotes, the McKennas published a string of over a dozen spy novels.
[1] The couple moved to Manchester during World War II and, despite her retirement, she was listed in 'The Black Book' of prominent subjects to be arrested by the Nazis in the case of a successful invasion of Britain.