 He was promoted to first lieutenant ("Oberleutnant") in April 1915.During an attack on the fortification at Thiaumont, Verdun, on 23 June 1916, he sustained a serious chest wound and spent the remainder of the war in France and Romania as a staff officer.He was awarded the Iron Cross First Class before being wounded at Verdun, and was promoted to captain ("Hauptmann") in April 1917.