From the age of nineteen, she aided the escape of nearly 140 airmen from occupied Belgium into France as part of the Comet Line.

[1] [2] In May 1940, shortly after the German occupation of Belgium, Hanotte and her father assisted two officers who had become separated during the retreat of the British Expeditionary Force to Dunkirk.

[1] Hanotte was subsequently recruited by the British War Office section, MI19 to actively participate in the Belgian resistance network called Comet Line, and was given the codename "Monique".

Over the course of the war, she and her family aided the escape of nearly 140 Allied forces airmen, either by accompanying them across the border, or travelling with them by train to cities such as Lille and Paris.

After travelling through German-occupied France to Spain (under Franco Dictatorship) via the Pyrenees, she reached Gibraltar, and from there flew to Britain.

Once there, she was taught to parachute and to be a secret agent in advance of being dropped into France as part of the Ardennes Counteroffensive of December 1944.

[4] In May 2015, a hiking circuit was opened to mark the route taken by Monique Hanotte to help airmen escape from Belgium into France.

[5] A statue of "Monique" was installed in Place de la Liberté in the French commune of Bachy, depicting her assisting American bombardier, Charles Carlson, to escape from Belgium.