 This cause of death is not mentioned in any other source, but it raises the interesting possibility that it was the crippling effects of this unidentified disease that led to Ímar's Old Norse sobriquet Ívarr inn beinlausi, or Ivar the Boneless.According to the Chronicle of the Kings of Alba, Amlaíb died around 874–875 in Dollar during a protracted campaign against Constantine I of Scotland.These deaths ushered in three decades of uncertainty for the Norse settlements in Ireland.