Thomas Börje Forsberg, better known by the stage name Quorthon, was a Swedish musician. He was one of the founders, as well as the sole songwriter, of the band Bathory, which pioneered the black metal genre and is credited with creating the Viking metal style. A multi-instrumentalist, Quorthon wrote the music and lyrics on all of Bathory's albums and performed vocals and guitars.

Bathory was a Swedish black metal band formed in Vällingby in March 1983. Named after Hungarian countess Elizabeth Báthory, they are considered pioneers of black metal and Viking metal. The book Lords of Chaos described Bathory's first four albums as "the blueprint for Scandinavian black metal." Acts influenced by their early records include Mayhem, Burzum, Darkthrone, Gorgoroth, Satyricon, Emperor, Dark Funeral, Enslaved, Immortal, Marduk, Moonsorrow and Dimmu Borgir.