[1][2] Arne Bergsgård was born in Vestre Slidre in Oppland and grew up in Vang, Norway.
In 1922, he was appointed a senior lecturer in history at the Norwegian College of General Sciences in Trondheim.
[3] During the occupation of Norway by Nazi Germany he joined the resistance movement, editing the underground publication I krigstid.
He was a member of the postwar investigation committee, Undersøkelseskommisjonen av 1945, where he wrote the appendix on the Norwegian Government's Foreign Policy up to April 1940.
[4] As a historian, he concentrated largely on the 19th century, primarily the emergence of Norwegian national identity.