Nazi Germany or the Third Reich was the period in the history of Germany from 1933 to 1945, when it was a dictatorship under the control of Adolf Hitler and the Nazi Party (NSDAP).Under Hitler's rule, Germany was transformed into a fascist totalitarian state which controlled nearly all aspects of life.Nazi Germany ceased to exist after the Allied Forces defeated Germany in May 1945, ending World War II in Europe.Hitler was appointed Chancellor of Germany by the President of the Weimar Republic Paul von Hindenburg on 30 January 1933.azi Germany made increasingly aggressive territorial demands, threatening war if they were not met. It seized Austria and Czechoslovakia in 1938 and 1939. Hitler made a pact with Joseph Stalin and invaded Poland in September 1939, launching World War II in Europe.