At the start of World War II, Ireland declared its neutrality and proclaimed "The Emergency". By July 1940, after Germany's military conquests of Poland, Denmark and Norway (Unternehmen Weserübung), as well as Luxembourg, Belgium, the Netherlands and France (Westfeldzug), Britain stood alone, with its Commonwealth and Empire against Nazi Germany. By May 1941, the German Air Force had bombed numerous British cities, including Belfast in Northern Ireland during "The Blitz". As part of the United Kingdom, Northern Ireland was at war, but the independent state of Ireland was neutral. German area bombings aimed at the United Kingdom were reduced after the launch of Operation Barbarossa in late June 1941.