Halfdan Olaus Christophersen
Halfdan Olaus Christophersen (13 December 1902 – 27 May 1980) was a Norwegian historian, literature researcher and non-fiction writer.

Personal life
Christophersen was born at Drammen  in Buskerud, Norway.  He was the second son of Tollef Christophersen (1878–1949) and Emma Langager (1880–1962).
After graduating artium in Arendal in 1921 he began studying philology at the University of Kristiania.

Career
Christophersen attended Wadham College at Oxford University under a Norwegian Oxford Scholorship. His doctorate thesis at Wadham College, Oxford was a treatment of John Locke (A Bibliographical Introduction to the Study of John Locke 1932). 
Christophersen became a Rockefeller Fellow in 1932 and was able to visit universities in Germany, Switzerland and the Netherlands before finishing at Stanford University in California.

From 1936 he became engaged as Secretary at the Institute of Higher International Studies (Institut des hautes études internationales)  in Paris. From  1940 Christophersen was a member of the  Chr. Michelsen Institute in Bergen, Norway.

During the occupation of Norway by Nazi Germany he was a central member of the Norwegian resistance movement. He was responsible for bringing Thorden Hessel Christophersen, his older brother and experienced seaman, into the movement. The eventual revelation that Hessel Christophersen was an informant to Vidkun Quisling's pro-Nazi regime resulted in a collapse in Olaus Christophersen's standing among his resistance movement peers and was a source of great shame for the remainder of his life. As a result of this private shame, he devoted himself to an undercover life as an active member of Hjemmefrontens Ledelse. After World War II, he served as director of the Department of Information Science and Media Studies at the University of Bergen (1946-1954).

He was editor of the three volumes of Den store krigen, published from 1946 to 1949. Among his other works are biographies of Marcus Jacob Monrad, Eilert Sundt and Niels Treschow. He wrote several books on the history of travelling and tourism, and World War II memoirs Fra nød til seir.

Publications

References

1902 births
1980 deaths
Writers from Drammen
Alumni of Wadham College, Oxford
Academic staff of the University of Bergen
20th-century Norwegian historians
Norwegian resistance members
Norwegian biographers
Male biographers
Norwegian memoirists
Locke scholars
20th-century Norwegian writers
20th-century Norwegian male writers
20th-century memoirists