He enlisted in the Prussian Army in 1913 and served as a machine gunner in the "König Karl" Grenadier Regiment 123, a part of the XIII (Royal Württemberg) Corps, on the Western Front of World War I, where he took part in the German invasion of Belgium and later fought in France. He received the Iron Cross 2nd Class and 1st Class, having been wounded six times, and finished the war with the rank of Lieutenant in charge of a company on the Eastern Front in southern Russia and Romania.[1] At the cessation of hostilities the German units in Dirlewanger's area were ordered to be interned in Romania, but Dirlewanger disobeyed orders and led 600 men from his and other units back to Germany.[3] According to German biographer Knut Stang, the war was a contributing factor that determined Dirlewanger's later life and his "terror warfare" methods, as "his amoral personality, with his alcoholism and his sadistic sexual orientation, was additionally shattered by the front experiences of the First World War and its frenzied violence and barbarism."[4]