Born in Bavaria in 1895, Hauser joined the army of Imperial Germany in 1914 as a Fahnen-junker (officer cadet) and served in the 17th Bavarian Infantry Regiment during World War I.

As an officer in the Heer (Army) branch of the Wehrmacht, he was on the staff of Generalleutnant[Note 1] Heinz Guderian's XIX Corps during the Invasion of Poland before being given command of the 18th Panzer Regiment in 1940.

[2] His new command was part of the newly formed 18th Panzer Division and went on to participate in Operation Barbarossa the following year and the subsequent battles along the centre of the Eastern Front.

Casualties and mechanical attrition were high across the division; at one stage, Hauser's regiment had only five tanks in operation and most personnel were fighting as infantry.

[4] On 1 September 1943, Hauser was appointed to command of the 13th Panzer Division, taking over from Hellmut von der Chevallerie who had been wounded.