Mayhem is a Norwegian black metal band formed in 1984 in Oslo. They were one of the founders of the Norwegian black metal scene and their music has strongly influenced the black metal genre. Mayhem's early career was highly controversial, primarily due to their notorious live performances, the 1991 suicide of vocalist Per Yngve Ohlin ("Dead") and the 1993 murder of guitarist Oystein Aarseth ("Euronymous") by former member Varg Vikernes ("Count Grishnackh"), of Burzum. The group released a demo and an EP that were highly influential, and amassed a loyal following through sporadic and notorious live performances, attracting further attention through their ties to the string of Norwegian church burnings and the incidents of violence surrounding them.

Statements of imminent touring plans were announced on the band's web page a few weeks after their final dates with Blasphemer. In October 2008, Krister Dreyer ("Morfeus") of Dimension F3H and Limbonic Art joined the group as touring guitarist for their upcoming South America Fucking Armageddon tour.  The band toured through late 2008 and 2009 with this lineup, prior to announcing Summer 2009 dates with Silmaeth, a French musician, as a second touring guitar. In November 2009, the band was arrested in Tilburg, Netherlands, after destroying a hotel room while on tour. Norwegian guitarist Teloch of Nidingr replaced Silmaeth in February 2011, and performed with the group before departing the following year.  In an interview in 2012, Necrobutcher revealed that Mayhem had begun work on their fifth studio album. As of November 2013, the new album was being mixed, with an early 2014 release date expected. Several months later, on February 18, 2014, it was announced that Mayhem would release a new album in May 2014, with a new song "Psywar" made available for streaming.  On February 20, 2014, the band's record label, Season of Mist, announced that the new album Esoteric Warfare would be released worldwide on May 27, 2014. This marked the first Mayhem studio effort since Blasphemer's departure and Teloch's permanent status in the band.  In January 2015, Mayhem, Watain, and Revenge played together as part of the "Black Metal Warfare" tour in the United States. Mayhem and Watain toured again in the United States in November 2015 with Rotting Christ as "Part II" of the previous tour.

What happened in 2008?
In October 2008, Krister Dreyer ("Morfeus") of Dimension F3H and Limbonic Art joined the group as touring guitarist for their upcoming South America Fucking Armageddon tour.