 After Ímar 's death , Diarmait appears to have appointed his own son , Murchad ( died 1070 ) , control of Dublin later that decade , as the Annals of the Four Masters accords him the title tigherna Gall , meaning " lord of the foreigners " in 1059 . In 1061 , Murchad invaded Mann and seems to have overthrown Echmarcach . Both father and son were dead by 1072 , and the Annals of Tigernach describes Diarmait on his death that year as King of the Isles ( rí Innsi Gall , literally " king of the isles of the foreigners " ) , a declaration which seems to indicate that , by the eleventh century at least , the kingship of the Isles was contingent upon control of Mann . 
