Career
His initial work was published in 1939, a children's book named Tore Kramkar. As his career progressed, Holt wrote many children's books, plays, radio plays, biographies, and historical novels. The trilogy Kongen about King Sverre Sigurdsson is considered his principal work.
He is also remembered for his mythologically-based novels about icons of Norwegian history, among others Kappløpet about Roald Amundsen which created a sensation when it was published in 1974.