It wouldn't be exaggerating to say that Mayhem was the foundation of black metal in Norway, and mainly responsible for all it's popularity.

guitarist and band-leader Euronymous had a shop in Oslo, Norway called "Helvete" (Norwegian for "Hell") and lots of impressionable teenagers hung out with him there and got hooked on his Satanic Black Metal philosophy.

Vocalist Dead (a Swede) commited suicide with a shotgun in 1991, leading to endless bootleg picture discs of his dead body, appearantly because Euronymous grabbed his camera before he bothered to call the cops and tell them what he found. Euronymous allegedly wore a piece of Dead's skull on a necklace. Dead was replaced in the recording studio by a Hungarian called Attila.

In 1993 Euronymous was murdered by Count Grishnackh from Burzum, who was at the time playing bass for Mayhem. Subsequent investigations brought to light a host of arsons against churches, and a lot of Euronymous' little followers got in trouble. The grim tale of Mayhem and Black Metal spread around the world, and suddenly Black Metal was very famous, and everyone started doing it.

Original drummer Hellhammer and bassist Necrobutcher got together with former vocalist Maniac and a new guitarist to relaunch Mayhem in 1997.

In 2004 Maniac leaves Mayhem and Attila Csihar rejoins as vocalist.

In 2007 Mayhem releases Ordo Ad Chao.

In 2008 Blasphemer leaves Mayhem to focus on his other project Ava Inferi.

In October 2008 it was announced that Morfeus from Limbonic Art would handle the guitar during Mayhem's South America tour.