Reidar Thomassen was born in
Harstad as a son of Lieutenant Colonel Haakon Ivar Thomassen (1895–1982) and nurse Edith Mack (1905–94). The family also lived in
Tromsø and
Narvik in Thomassen's youth. From 1964 to 1979 he was married to teacher Inger Sofie Lund. He resided in
Bærum Municipality. Thomassen
finished his secondary education in Narvik in 1956, took military training in Harstad and studied at the
University of Oslo. He graduated with the
cand.real. degree in geography in 1964. He worked as az teacher from 1965 to 1972 and editor from 1972 to 1985, among others for the magazine
Teknisk Presse. In 1985 he took up writing full-time. ==References==