In May 1913 Hitler left Vienna for Munich and, when war broke out in August 1914, he joined the Sixteenth Bavarian Infantry Regiment, serving as a despatch runner. Hitler proved an able, courageous soldier, receiving the Iron Cross (First Class) for bravery, but did not rise above the rank of Lance Corporal. Temporarily blinded and driven to impotent rage by the abortive November 1918 revolution in Germany as well as the military defeat, Hitler, once restored, was convinced that fate had chosen him to rescue a humiliated nation from the shackles of the Versailles Treaty, from Bolsheviks and Jews.
Assigned by the Reichswehr in the summer of 1919 to "educational" duties which consisted largely of spying on political parties in the overheated atmosphere of post-revolutionary Munich, Hitler was sent to investigate a small nationalistic group of idealists, the German Workers' Party. On 16 September 1919 he entered the Party (which had approximately forty members), soon changed its name to the National Socialist German Workers' Party (NSDAP) and had imposed himself as its Chairman by July 1921.