He was a colonel and regiment chief from 1911. He was commander leader of the Søndermør Infantry Regiment until 1914 and of the Smaalenene Infantry Regiment until 1918. He joined the French Foreign Legion in 1918, and participated on the Western Front for France in World War I. It was whilst he was deployed in Northern Russia that he had a severe case of frostbite, resulting in both of his feet and several fingers being amputated. He was appointed as an officer of the Legion of Honour for his service during the North Russia intervention.