Answer: By 1942, Nazi Germany controlled a significant portion of Europe, including:
Germany: Nazi Germany was the centre of the Axis powers.
Austria: Germany annexed Austria in 1938 in the Anschluss.
Czechoslovakia: Germany invaded and occupied Czechoslovakia in 1939.
Poland: Germany invaded and occupied Poland in 1939, which sparked the beginning of World War II.
Denmark: Germany occupied Denmark in 1940.
Norway: Germany occupied Norway in 1940.
The Netherlands: Germany invaded and occupied the Netherlands in 1940.
Belgium: Germany invaded and occupied Belgium in 1940.
Luxembourg: Germany invaded and occupied Luxembourg in 1940.
France: Germany invaded and occupied France in 1940.
Yugoslavia: Germany invaded and occupied Yugoslavia in 1941.
Greece: Germany invaded and occupied Greece in 1941.
Soviet Union: Germany invaded the Soviet Union in 1941 and had made significant gains by 1942, including control over modern-day Ukraine, Belarus, Estonia, Latvia, and Lithuania.