Kolbeinn used his influence to ensure that men in his favour received positions of power within the clergy, amongst them bishop Guðmundur Arason.
Guðmundur, unbeknownst to Kolbeinn, proved to be an advocate of clerical independence and resented interference from the secular chieftains.
In 1208, Kolbeinn and his followers attacked Guðmundur and his supporters in Hjaltadalur by Víðines.
Notwithstanding his opposition to bishop Guðmundur, sources indicate that Kolbeinn was a devoutly religious man of some education.
He is best known for composing the hymn Heyr himna smiður (English: "Hear, Smith of heavens") on his deathbed.