Who is Ketil Firebeard Ketilson from Avalon?

Ketil is a Viking and the owner of the ship, the Byglia. He twice raids Padstow, where he fathers Merewyn. Unfortunately, Merewyn is a child of rape. During his second raid, he takes Merewyn captive, completely unaware that she is his daughter. Ketil dies on the journey to Greenland.