The involvement of the Grand Duchy of Luxembourg in World War II began with its invasion by German forces on 10 May 1940 and lasted beyond its liberation by Allied forces in late 1944 and early 1945.
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.