Resistance groups were active throughout German-occupied France and made important contributions to the Allied invasion of Normandy in June 1944. Members of the Resistance provided the Allies with intelligence on German defences and carried out acts of sabotage to disrupt the German war effort.
The rail network was a particular focus of resistance activities, especially in the time leading up to D-Day. Both tracks and trains were deliberately damaged to put the railways out of action. Non-violent acts of resistance such as strikes and go-slows were used to great effect, particularly by railway workers, to delay the movement of German troops and supplies to the invasion area. Factories and industrial centres were also targeted to slow war production.
Special Operations Executive (SOE) had been set up in 1940 to coordinate and carry out subversive action against German forces in occupied countries, including France. SOE sent agents to support resistance groups and provided them with weapons, sabotage materials and other supplies.
There was only limited cooperation between SOE and those planning Operation ‘Overlord’, and the exact role resistance forces would have during the invasion was not decided until the week before D-Day. There were also differences between the many groups that made up French resistance – each had different origins, methods and political aims – as well as rivalries between the various intelligence organisations, including SOE. This made it difficult to effectively coordinate their activities.
Secret messages were broadcast on the eve of D-Day alerting SOE agents and resistance forces to make ‘maximum effort’ in carrying out acts of sabotage. Earlier messages warning of the impending invasion had been broadcast on 1 May and 1 June. These were picked up by the Nazi Security Services and reported to the High Command. But these warnings were not acted upon and therefore did not endanger the landings by giving away the element of surprise.
On and shortly after D-Day, three-man special forces ‘Jedburgh’ teams made up of British, American and French personnel in uniform were dropped into France to align French resistance activities with Allied strategy. They also helped to undermine German defences in Normandy by disabling rail, communication and power networks in the invasion area. This disruption helped prevent the Germans from concentrating their strength in Normandy on D-Day and in the weeks that followed.