Formed in 1982, seminal Swiss extreme heavy metal band Hellhammer toyed with Satanic imagery, but were chiefly concerned with generating morbid intensity. Generally considered to be formless noise at the time, Hellhammer attracted a cult following nonetheless. They appealed to the youthful grass-roots of the heavy metal scene, who coveted the most bombastically abrasive sounds that could be committed to vinyl. Extreme metal cognoscenti often cite Hellhammer as the first true death metal band and their early demos are still regarded as underground classics by some. Nevertheless, they undeniably lacked maturity and subtlety - as evidenced by the band members' stage names: Satanic Slaughter (b. Thomas Fischer, vocals), Savage Damage (bass) and Bloodhunter (b. Bruce Day; drums). Satanic Slaughter and Savage Damage, under the names Thomas Gabriel Warrior and Martin Eric Ain, respectively, went on to form the better-realized thrash band Celtic Frost in 1984, having recorded only one mini-LP as Hellhammer.
Source: http://www.spirit-of-metal.com/biographie-groupe-Hellhammer-id_bio-1402-l-en.html