Luxembourg was placed under occupation and was annexed into Germany in 1942. During the occupation, the German authorities orchestrated a programme of "Germanisation" of the country, suppressing non-German languages and customs and conscripting Luxembourgers into the Wehrmacht, which led to extensive resistance, culminating in a general strike in August 1942 against conscription. The Germanisation was facilitated by a collaborationist political group, the Volksdeutsche Bewegung, founded shortly after the occupation. Shortly before the surrender, the government had fled the country along with Grand Duchess Charlotte, eventually arriving in London, where a Government-in-exile was formed. Luxembourgish soldiers also fought in Allied units until liberation.
The Luxembourg government had pursued a policy of neutrality since the Luxembourg Crisis of 1867 had highlighted the country's vulnerability. During the First World War, the 400 men of the Corps des Gendarmes et Volontaires had remained in barracks throughout the German occupation. In March 1939, in a speech to the Reichstag, Adolf Hitler promised that Luxembourg sovereignty would not be breached.
The strength of the military was gradually increased as international tension rose during Appeasement and after Britain and France's declaration of war against Germany in September 1939. By 1940, the Luxembourg army numbered some 13 officers, 255 armed gendarmes and 425 soldiers.
The popular English-language radio station Radio Luxembourg was taken off-air in September 1939, amid fears that it might antagonize the Germans. Apart from that, normal life continued in Luxembourg during the Phoney War; no blackout was enforced and regular trains to France and Germany continued.
In Spring 1940, work began on a series of roadblocks across Luxembourg's eastern border with Germany. The fortifications, known as the Schuster Line, were largely made of steel and concrete.