Vikernes founded Burzum in 1991 and recorded the first four Burzum albums between January 1992 and March 1993. From 1994 to 2009, Vikernes was imprisoned for the murder of Mayhem guitarist Øystein "Euronymous" Aarseth and the arson of three churches. While imprisoned, he recorded two dark ambient albums using only synthesizers, as he had no access to drums, guitar, or bass.