 Contemporary annals suggest that Óttar was co-king with Ragnall mac Torcaill, until Ragnall was killed in a battle against the forces of Midhe (Meath) in 1145 or 1146.Óttar retained control of Dublin until 1148 when he was "treacherously killed" by Ragnall's kin, the Meic Torcaill.Óttar of Dublin's son Thorfin was described as the most powerful "princeps" (jarl) of the Hebrides.