Ihsahn (born October 10, 1975 as Vegard Sverre Tveitan) is a Norwegian composer, guitar, bass, keyboard player and vocalist. He is best known for his work with Norwegian black metal band Emperor. He has appeared in Thou Shalt Suffer, up until March 4, 2006, played in Peccatum with his wife Ihriel (real name Heidi S. Tveitan), and now devotes himself to his solo albums. In his very early releases, he went by the name Ygg.