The military career of Adolf Hitler can be divided into two distinct portions of Adolf Hitler's life. Mainly, the period during World War I when Hitler served as a Gefreiter (lance corporal) in the Bavarian Army, and the era of World War II when Hitler served as the Supreme Commander-in-Chief of the Wehrmacht (German Armed Forces) through his position as Führer of Nazi Germany.
Hitler received the final part of his father's estate in May 1913 and moved to Munich, where he earned money painting architectural scenes. He may have left Vienna to evade conscription into the Austrian Army. Hitler later claimed that he did not wish to serve the Habsburg Empire because of the mixture of "races" in its army. The Bavarian police sent him back to Salzburg for induction into the Austrian Army, but he failed his physical exam on 5 February 1914 and returned to Munich.
He was 25 years old in August 1914, when Austria-Hungary and the German Empire entered the First World War. Because of his Austrian citizenship, he had to request permission to serve in the Bavarian Army. Permission was granted. On the evidence of a report by the Bavarian authorities in 1924, which questioned how Hitler was allowed to serve in the Bavarian Army, Hitler almost certainly was enlisted through an error on the part of the government. The authorities could not explain why he was not deported back to Austria in 1914 after he failed his physical exam for the Austrian Army; they concluded that the matter of Hitler's citizenship was simply not raised, thus he was allowed to enter the Bavarian Army. In the army, Hitler continued to put forth his German nationalist ideas which he developed from a young age.
During the war, Hitler served in France and Belgium in the 16th Bavarian Reserve Regiment. He was an infantryman in the 1st Company during the First Battle of Ypres (October 1914), which Germans remember as the Kindermord bei Ypern (Ypres Massacre of the Innocents) because approximately 40,000 men (between a third and a half) of nine newly-enlisted infantry divisions became casualties in 20 days. Hitler's regiment entered the battle with 3,600 men and at its end mustered 611. The regimental commander (Julius List) was killed and thereafter they became known as the List Regiment in his honor. By December Hitler's own company of 250 was reduced to 42. Biographer John Keegan claims that this experience drove Hitler to become aloof and withdrawn for the remaining years of war. After the battle, Hitler was promoted from Schütze (Private) to Gefreiter (Lance Corporal) and assigned to be a regimental message-runner.
Some have regarded this assignment as "a relatively safe job", because regimental headquarters was often several miles behind the Front. According to Thomas Weber of the University of Aberdeen, earlier historians of the period had not distinguished between regimental runners, who were based away from the front "in relative comfort", and company, or battalion runners, who moved among the trenches and were more often under fire.