This profile is solely documented in a history of the Grant clan, which claims descent through Håkon Jarl:

Hacken Grant, Lord Protector of Norway, was honorably married, and begat five Sons - their narnes are Erling, the eldest, when but eleven years of age sacrificed in favor of his progenitor Oudine; Hemming, the second and representative married to Tora, daughter to the King of Denmark, of whom the name of Grant is descended; Svend is the third son, married to Imgcharg, daughter to Olaus King of Sweden - of them are the two great families of Breide in Holstein and the Prince of Cimberne in Germany descended. Hacken was the name of the fourth Son, he was married to Helena, Daughter to the Earl of Darley in England; and Peter, begotten in fornication, was his fifth son, he was Stuart to the King of Denmark.

http://www.clangrant.org/index.aspx?pid=14&highlight=monymusk