In 1940, after the outbreak of World War II, Luxembourg's neutrality was violated again when Nazi Germany's Wehrmacht entered the country, "entirely without justification". In contrast to the First World War, under the German occupation of Luxembourg during World War II, the country was treated as German territory and informally annexed to the adjacent province of the Third Reich, Gau Moselland. This time, Luxembourg did not remain neutral as Luxembourg's government in exile based in London supported the Allies, sending a small group of volunteers who participated in the Normandy invasion, and multiple resistance groups formed inside the occupied country.