Quorthon (born Tomas Forsberg February 17, 1966, Stockholm, died June 7, 2004, Stockholm) was a Swedish musician. He was a multi-instrumentalist and the founder and songwriter of the pioneering Swedish black metal band Bathory. He is also credited with creating the Viking metal genre. He composed the music and wrote the lyrics on all of Bathory's albums.

Quorthon was found dead in his apartment on 7 June 2004, apparently from heart failure.

Source:  http://en.wikipedia.org/wiki/Quorthon