The countries invaded by Nazi Germany were Austria(March 1938), Czechoslovakia(Aug. 1939), Poland(Sept. 1939, June 1941), France(May 1940), Denmark(April 1940), Norway(April 1940), Belgium(May 1940), Netherlands(May 1940), Yugoslavia(April 1941), Sudetenland (Oct. 1938), Greece(April 1941), [Estonia, Latvia, Lithuania](June 1941), and The Soviet Union(June 1941).  Italy wasn't invaded but it was occupied by Germany in September 1943.