Vegard Sverre Tveitan (born 10 October 1975), better known as Ihsahn (), is a Norwegian multi-instrumentalist, singer, and composer, best known for his work with black metal band Emperor. Tveitan is also a founding member of Thou Shalt Suffer, where he played guitar and keyboard in addition to vocal duties, and Peccatum, a project in collaboration with his wife and fellow musician Heidi Solberg Tveitan, also known as Starofash. Since 2006, Tveitan has primarily devoted himself to solo albums and occasional guest appearances.