 Before the end of 871, Amlaíb returned to Scotland to suppress a Norse uprising against his father Gofraid mac Ragnaill.During this time (871–872), Ímar and Amlaíb's son Oistín (Eysteinn) plundered Ireland "from east to west and from north to south".By 878 the Findgaill and Dubgaill were dominant in many parts of Britain, controlling territories in Scotland, Strathclyde, Northumbria, East Anglia, Wales and Mercia.