[1] Haakonsson was born the son of jarl Haakon the Crazy (Håkon Galen) and Swedish noble-woman Kristina Nilsdotter.
He subsequently married Ingrid, a daughter of jarl Skule Baardsson, who had a form of power sharing with King Haakon.
Knut rejected Skule's advances and remained loyal to King Haakon, who subsequently elevated him to jarl.
For the rest of his life, Knut retained the title of jarl, which formally made him the highest ranking man in the country after the king and his sons.
In September 1261, he carried the crown at the coronation ceremony of Haakon's son, King Magnus VI of Norway.