 He was arrested in Sweden for his involvement with Norwegian resistance activity in the country in 1941, and was sent to the United Kingdom where he joined the Norwegian Independent Company 1 ("Kompani Linge") and received British military training.He was deployed to Norway in 1943 as part of Lark, assigned with establishing radio connection with London.He led Lark in Trøndelag between 1943 and 1945, which constituted the leadership of Milorg in the region.