 Óláfr was a member of the Crovan dynasty of sea @-@ kings , a younger son of Guðrøðr Óláfsson , King of the Isles , King of Dublin ( d . 1187 ) , and grandson of Óláfr Guðrøðarson , King of the Isles ( d . 1153 ) . Guðrøðr inherited a vast island @-@ kingdom from his father , which encompassed the Hebrides — situated on the western seaboard of Scotland — and the Isle of Man ( Mann ) , located in the middle of the northern Irish Sea , a strategically important point approximately equidistant from the islands of Great Britain and Ireland . In the mid 12th century Guðrøðr lost control of much of the Inner Hebrides to Somairle , Lord of Argyll , and was unable to regain these islands on Somairle 's death in 1164 . Like his predecessors , Guðrøðr is sometimes anachronistically styled " King of Mann " in secondary sources . This is because Guðrøðr , his sons Rögnvaldr and Óláfr , and his father Óláfr styled themselves Rex Insularum ( " King of the Isles " ) ; it was not until the reigns of Guðrøðr 's grandsons ( Óláfr 's sons ) that the leading members of the dynasty adopted the Latin title Rex Mannie et Insularum ( " King of Mann and the Isles " ) . 
