 In 1989, aged 17, Grutle and his 13-year-old friend, guitarist Ivar Bjørnson and other musicians, founded death metal band Phobia, but they left the project in mid-1991.At that time, both and drummer Trym Torson decided to form a band inspired by Norse mythology called Enslaved, in Haugesund.Kjellson and Bjørnson are the only permanent members of Enslaved since its inception to date.