Hausser served as an officer in the Prussian Army during World War I and attained the rank of general in the inter-war "Reichsheer". After retirement, he joined the SS and was instrumental in forming the Waffen-SS. During World War II, he rose to the level of army group commander. He led Waffen-SS troops in the Third Battle of Kharkov, the Battle of Kursk and the Normandy Campaign. Hausser was the highest-ranking officer in the Waffen-SS alongside Sepp Dietrich. Unlike Dietrich, Hausser was a trained staff officer before joining the SS.