Immortal was started by Abbath and Demonaz in 1990, and they were joined by a string of drummers who typically lasted one album, until settling on Horgh for their fourth album "Blizzard Beasts".
In 1998 Demonaz developed an injury to his arm, meaning that he could no longer play the guitar and had to quit the band, although he kept providing lyrics for them.
Immortal split-up in 2003, but has since of 2006 reformed.