 Cerball next appears to have allied himself with two Norse or Norse-Gael "kings", Amlaíb Conung, "son of the king of Lochlann", and Ímar, called "king of the Norsemen of all Ireland and Britain" at his death in 873.Ímar is sometimes assumed to be the same person as Ivar the Boneless and Amlaíb to be Olaf the White, respectively son and grandson of the legendary Swedish king Ragnar Lodbrok, although this is far from certain.These allies were not sufficiently strong to prevent Máel Sechnaill from taking hostages and tribute from Cerball in 858, but Cerball and Ímar campaigned in Leinster that year, and also against the Norse-Gaels in Munster.