The Big Four
United Kingdom / Great Britain September 1939
Soviet Union June 1941
United States Dec. 1941
Republic of China 1942
Occupied Allied Countries by Axis Powers
Poland invaded on September 1, 1939
France invaded on September 3, 1939
Norway invaded on April 8, 1940
Denmark invaded on April 9, 1940
Belgium, Luxembourg, & Netherlands invaded on May 10, 1940
Greece invaded on October 28, 1940
Nazi Germany / German Reich 1933-1945
Kingdom of Italy (1922-1943 controlled by Benito Mussolini), 1939-1943 / Italian Social Republic, 1943-1945
Empire of Japan 1940: Japan invaded China in 1937, starting the Second Sino-Japanese War, 1937-1945