From Wikipedia
The German Luftwaffe was one of the strongest, most doctrinally advanced, and most battle-experienced air forces in the world when World War II started in Europe in September 1939. Officially unveiled in 1935, in violation of the Treaty of Versailles, its purpose was to support Adolf Hitler's Blitzkrieg across Europe. The aircraft that were to serve in the Luftwaffe were of a new age and far superior to that of most other nations in the 1930s. Types like the Junkers Ju 87 Stuka and Messerschmitt Bf 109 came to symbolize German aerial might.