Óláfr's allotment in Rǫgnvaldr's island-kingdom appears to have been Lewis and Harris. When confronted by Óláfr for more territory, Rǫgnvaldr had him seized and incarcerated by the Scots. After almost seven years in captivity, Óláfr was released in 1214, and Rǫgnvaldr arranged for him to marry the sister of his own wife. Óláfr was able to have this marriage annulled, sometime after 1217, whereupon he married the daughter of a rising Scottish magnate. Outright warfare broke out between the half-brothers in the 1220s, and Óláfr's gains forced Rǫgnvaldr to turn to the powerful Alan fitz Roland, Lord of Galloway. Rǫgnvaldr and Alan bound themselves through the marriage of a daughter of Rǫgnvaldr to Alan's illegitimate son, Thomas. The prospect of a future Gallovidian king prompted the Manxmen to depose Rǫgnvaldr in favour of Óláfr. Although Rǫgnvaldr was initially aided against Óláfr by Alan and his family, Gallovidian military support dramatically diminished over time. On 14 February 1229, the forces of Rǫgnvaldr and Óláfr clashed for the last time, and Rǫgnvaldr himself was slain. His body was conveyed to St Mary's Abbey, Furness and buried.