On 1 August 1914, shortly after the start of World War I, Jünger volunteered with the 73rd Infantry Regiment "Albrecht von Preussen" of the Hannoverian 19th Division and after training was transported to the Champagne front in December. He was wounded for the first time in April 1915. During convalescence, he decided to enlist as an officer aspirant ("Fahnenjunker"), and he was promoted to Lieutenant on 27 November 1915. As platoon leader, he gained a reputation for his combat exploits and initiative in offensive patrolling and reconnaissance.