Hellhammer were a metal band from Switzerland that are credited as being pioneers of extreme metal and the black metal genre, along with Venom and Bathory in the early 1980’s. Formed by Tom G Warrior and Martin Eric Ain (who went on to form Celtic Frost) Apocalyptic Raids was originally released in 1984 and is a cult classic that is revered as a hugely influential release, that laid the blueprint for extreme metal as a whole.