[1] He was born in Vang, Hedmark as a son of professor Werner Hosewinckel Christie (1877–1927) and Karen Amalie Wedel-Jarlsberg (1886–1952).
As World War II broke out, Christie, with the rank of sergeant, was called to Sola Airport as a member of Norway's neutrality guard.
Norway eventually fell to German rule, and in the autumn of 1940 Christie fled to Canada via Sweden, the Soviet Union and the United States.
He graduated from the RAF Staff College in 1946, worked for the Scandinavian Airlines System from 1947 to 1949 and as the aerial attaché at the Norwegian embassy in Stockholm from 1949 to 1951.
He was appointed as head of the Norwegian Air Force High Command (Luftforsvarets overkommando) in 1951, with the rank of major, but did not stay for long.