A Reichsgau was an administrative subdivision created in a number of areas annexed by Nazi Germany between 1938 and 1945.
Propaganda postcard of Nazi Germany depicting the Gaue of the Reich (October 1939)
Areas annexed by Nazi Germany
There were many areas annexed by Nazi Germany both immediately before and throughout the course of World War II. Territories that were part of Germany before the annexations were known as the "Altreich".
Adolf Hitler greeted by cheering crowds in Vienna, following the annexation of Austria into the III Reich, 15 March 1938
Execution of local Polish people in the town of Kórnik, after the German invasion of Poland, 20 October 1939