Current line-up:
Ihsahn (Vegard Sverre Tveitan) : Vocals, Guitars, Bass, Synths/Keys (1991-) (Zyklon-B (Nor), Peccatum, Thou Shalt Suffer, Wongraven, Ildjarn, Embryonic, Hardingrock)
Samoth (Tomas Thormodsaeter Haugen) : Guitars, Drums on "Wrath of the Tyrant" (1991-) (Zyklon, Thou Shalt Suffer, Gorgoroth, Satyricon, Zyklon-B (Nor), Ildjarn, session for Burzum, Arcturus (Nor), Scum (Nor), Embryonic, Xerasia)
Trym Torson (Kai Johnny Mosaker) : Drums (1996-) (Enslaved (Nor), Imperium (Nor), Shadow Season, Tartaros (Nor), Zyklon, Paganize, Ceremony (US), Abigail Williams (session))

Live Musicians:
Secthdaemon (Odd Tony) : Bass (2005-) (Myrkskog, Odium (Nor), Zyklon, Kill All)
Einar Solberg - Synths/Keys (2005-) (Leprous)Former/past member(s) Bass:
Mortiis (Haavard Ellefsen) (1993) (Vond, Cintecele Diavolui, Fata Morgana (Nor))
Tchort (Terje Vik Schei) (1993-1994) (Blood Red Throne, Carpathian Forest, Green Carnation, Satyricon)
Jonas Alver (1995-1998) (Dшdheimsgard)

Drums:
Faust (Bard Eithun) (1993-1994) (Thorns, Zyklon, Impostor/Death Fuck, Aborym (Ita), Scum (Nor), Decomposed Cunt, Blood Tsunami, Stigma Diabolicum, Hesperus Dimension)

Live musicians:
Tyr (Jan Erik Torgersen) : Bass (1998-2001) (Borknagar, Vintersorg, Thornbound)
Charmand Grimloch (Joachim Rygg) : Synths/Keys (1998-2001) (Tartaros (Nor), Souls Domain)