http://en.wikipedia.org/wiki/Harald_Grenske
Harald Grenski (
10th century) was the son of
Gudrød Bjørnsson. Gudrød was a grandson of
Harald Fairhair, and the king of
Vestfold.
Harald's cognomen Grenski is due to his being raised in the district of
Grenland,
Norway. His father was slain when Harald was only 11 years old, by the sons of
Gunnhild (i.e.
Harald Greyhide and his brothers). Harald fled to
Oppland and from there to
Sweden, where he stayed with the powerful strongman
Skagul Toste. He spent the summers pillaging as a
Viking.
When the sons of Gunnhild had been banished, Harald Grenske followed
Harald Bluetooth and
Haakon Sigurdsson to Norway, and under Danish sovereignty, Harald became the king of Vestfold and
Agder. He married
Asta, the daughter of
Gudbrand Kula, but abandoned her to woo
Sigrid the Haughty, the daughter of Skagul Toste.
As Sigrid found him too eager with his entreaties, she had him burnt to death inside a house. His widow, Asta, promptly gave birth to the son
Olaf the Stout, a future king of Norway, and was later remarried to
Sigurd Syr, the king of
Ringerike.