 In 1044 , the Annals of Tigernach records that Ímar penetrated into the domain of the Uí <unk> <unk> <unk> and killed their chief . The annal @-@ entry also indicates that Ímar stormed the church of Armagh , and burned <unk> <unk> ( the " Shrine of Patrick " ) in the attack . The following year , he again invaded Rathlin Island , and his subsequent slaughter of three hundred noblemen of the Ulaid , including a certain heir apparent named <unk> Ua <unk> , is documented by the Annals of Clonmacnoise , the Annals of Inisfallen , the Annals of Tigernach , and the Annals of the Four Masters . This remarkable action may indicate that the Dubliners and Ulaid were battling for control of Rathlin Island . If so , it could be evidence that Ímar enjoyed the possession of Mann by this date . The domain of the Ulaid is certainly the closest Irish territory to Mann , and the control of the <unk> fleet could account for the <unk> 's ability to challenge the Ulaid . Whatever the case , within the year Niall mac <unk> , King of Ulaid ( died 1063 ) is recorded to have attacked Fine Gall — Dublin 's <unk> @-@ rich northern hinterland — in what may have been a retaliatory raid . 
