 He is sometimes identified with Thorstein the Red, a figure who features in the Norse sagas.The earliest mention of Oistin may be by "Cogad Gáedel re Gallaib", which in 873 describes how Bárid mac Ímair and an unnamed son of Amlaíb Conung plundered the caves of Ciarraige.This unnamed son of Amlaíb is probably Oistin.