Kolbeinn ungi Arnórsson (1208 â 22 July 1245) was an Icelandic chieftain or goði of the ÃÂsbirningar family clan. He fought with Gissur ÃÂorvaldsson against the Sturlungs in the Icelandic civil war during the Age of the Sturlungs. His homestead was in VÃÂðimýri in Skagafjörður. He was married to Hallbera Snorradóttir, the daughter of Icelandic historian and poet Snorri Sturluson.