Fagrskinna and Heimskringla both agree that Halfdan's first wife was Ragnhild, daughter of King Harald Gulskeg (Goldbeard) of Sogn. Halfdan and Ragnhild had a son named "Harald" after his grandfather, and they sent him to be raised at his grandfather's court. Harald Gulskeg, being elderly, named his grandson as his successor, shortly before his death. Ragnhild died shortly after her father, and the young king Harald fell sick and died the next spring. When Halfdan heard about his son's death, he travelled to Sogn and laid claim to the title of king. No resistance was offered, and Halfdan added Sogn to his realm.
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