What was the name of the father of the Norwegian king at the center of the Saga of Harald Fairhair?
Halfdan the Black Halfdan the Black (Old Norse: "Halfdanr Svarti") (  810 –  860 ) was a ninth-century king of Vestfold. He belonged to the House of Yngling and was the father of Harald Fairhair, the first king of Norway.
Ímar Ímar (Old Norse: "Ívarr" ; died c. 873) was a Viking leader in Ireland and Scotland in the mid-late ninth century who founded the Uí Ímair dynasty, and whose descendants would go on to dominate the Irish Sea region for several centuries. He was the son of the king of Lochlann, identified in the non-contemporary "Fragmentary Annals of Ireland" as Gofraid. The "Fragmentary Annals" name Auisle and Amlaíb Conung as his brothers. Another Viking leader, Halfdan Ragnarsson, is considered by some scholars to be another brother. The Irish Annals title Amlaíb, Ímar and Auisle "kings of the foreigners". Modern scholars use the title "kings of Dublin" after the Viking settlement which formed the base of their power. Some scholars consider Ímar to be identical to Ivar the Boneless, a Viking commander of the Great Heathen Army named in contemporary English sources who also appears in the Icelandic sagas as a son of the legendary Viking Ragnar Lodbrok.