 It is <unk> that Ímar received some form of support from Knútr 's son and successor in Britain , Haraldr <unk> , King of England ( died <unk> ) . The latter was certainly in power when Ímar replaced Echmarcach , and an association between Ímar and Haraldr could explain why the Annals of Ulster reports the latter 's death two years later . Ímar 's reign lasted about eight years , and one of his first royal acts appears to have been the invasion of Rathlin Island within the year . The fact that he proceeded to campaign in the North Channel could indicate that Echmarcach had held power in this region before his acquisition of Mann and Dublin . 
