[1] He was born in Porsgrunn as a son of assurance director Olaf Karenius Abrahamsen (1853–1936) and Caroline Marie Halvorsen (1855–1925).
[2][3] He originally worked as an engineer, graduating from Skiensfjorden Mechanical Vocational School in 1904 and a technical college in Germany in 1907.
He then attended the Norwegian National Academy of Fine Arts where he studied under Halfdan Strøm and Christian Krohg from 1912 to 1913 and the Norwegian National Academy of Craft and Art Industry under Johan Nordhagen from 1913 to 1915.
[3] During the German occupation of Norway he was a member of the Temporary Consultative Arts Council from November 1940 till 1942, and then of the Cultural Assembly (Norwegian: Kulturtinget) until the war's end.
In 1958 he finally managed to exhibit the series of seven grand paintings, Draumkvædet, on which he had worked for thirty years.