[2] He spent part of his childhood in Brussels, where his father had a position as secretary-general of the Inter-Parliamentary Union.

[1] Lange finished his secondary education in 1924, enrolled subsequently at the University of Oslo where he studied history, and graduated as cand.philol.

[1] He was arrested in June 1941 and held at Møllergata 19 until October 1941, at Grini concentration camp from October 1941 to April 1943, and at the Sachsenhausen concentration camp until the end of World War II.

[3] He issued the book 3 fra Sachsenhausen in 1945, together with Carl Johan Frederik Jakhelln and Olav Larssen,[4] where he wrote the article "Ved livets grense" about Norwegian prisoners in Sachsenhausen.

[1] In 1946 and 1947 the two-volume book Griniboken was issued, edited by Lange and Johan Schreiner, with contributions from several of the prisoners at Grini.