Louis Cachet (born Kristian Vikernes; 11 February 1973), better known as Varg Vikernes (Norwegian: [ˈvɑrɡ ˈvìːkəɳeːs]), is a Norwegian musician and author best known for his early black metal albums and later for his crimes. His first five records, released under the name Burzum from 1992 to 1996, made him one of the most influential figures in the early Norwegian black metal scene. He was convicted of murder and arson in 1994 and sentenced to 21 years in prison, being released after serving 15 years.

A native of Fana in Bergen Municipality, Vikernes began playing guitar at the age of 14 and formed his first band, Kalashnikov (later known as Uruk-Hai), by 1989. He went on to join the band Old Funeral, in which he played guitar from 1989 until his departure in 1991. He recorded multiple tracks with the band, which were featured on the Devoured Carcass EP, as well as various compilation albums released years later. In 1992, Vikernes, along with other members of the scene, was suspected of burning down four Christian churches in Norway. Vikernes denied committing the arsons, though he supported them. In 1992–1993, he also recorded bass for Mayhem's debut studio album De Mysteriis Dom Sathanas (1994).

In August 1993, Vikernes fatally stabbed Mayhem guitarist Euronymous during an altercation at the latter's apartment, and was arrested shortly after. In May 1994, Vikernes was convicted of first-degree murder, church arson and possession of explosives. Vikernes has always maintained the killing was self-defense, and unsuccessfully argued for the charge to be reduced to voluntary manslaughter. He was sentenced to 21 years in prison, the maximum penalty under Norwegian law. During his incarceration, Vikernes launched the neo-Nazi organisation Norwegian Heathen Front, had two books published, and released two ambient albums as Burzum. In 2009, he was released on parole, after which he moved to France with his wife and children, where he has continued to write and make music. He was also an active video blogger on his YouTube channel ThuleanPerspective, before the channel was banned by the platform.

Described by Sam Dunn as "the most notorious metal musician of all time", Vikernes remains controversial for his crimes as well as his political and religious views. He promoted views which combined Odinism and Esoteric Nazism, and openly embraced Nazism during the mid-to-late 1990s. He has continued to be associated with far-right politics. Vikernes calls his beliefs "Odalism" and defends a "pre-industrial European pagan society" that opposes the Abrahamic religions and systems such as capitalism, communism, materialism, and socialism.

Vikernes was born on 11 February 1973 in Bergen. In the interviews printed in the 1998 book Lords of Chaos, Vikernes discusses his background and childhood. Lords of Chaos also includes an interview with his mother, Helene Bore (the book and a newspaper depicted there refer to her with the given name Lene, whereas Vikernes' own website uses the name Helene. In a 2004 interview, Vikernes said his mother was "working in a large oil company". His father is an electronics engineer, and his older brother is a civil engineer.

In the Lords of Chaos interview, Vikernes recalls that when he was 6 years old, the family moved for about a year to Baghdad, Iraq, because Vikernes' "father was working for Saddam Hussein" developing a computer program. Since there were no places available in the English school in Baghdad, the young Vikernes went to an Iraqi elementary school during this time. According to his interview, Vikernes here became "aware of racial matters". Corporal punishment was very common in the school, and on one occasion, Vikernes had a "quarrel" with a teacher and called him "a monkey". But as Vikernes perceived it the teachers "didn't dare to hit me because I was white". Vikernes' mother also recalls that "the other children in his class would get slapped by their teachers; he would not". She mentions that this created problems, but generally she "has no good explanation" of how Varg developed his views.

When asked about his father, Vikernes states that he was hysterical that his son "had a swastika flag at home". Vikernes feels that his father was a hypocrite because he was worried about Vikernes "being a Nazi", whereas he too was "pissed about all the colored people he saw in town". About his mother, Vikernes states that she was "very race conscious", in the sense that she was afraid that Vikernes "was going to come home with a black girl!" At the time of the 1995 Lords of Chaos interview, Vikernes still had a positive relationship with his mother but "very little contact" with his father. He also stated that his parents are divorced; Vikernes' father is said to have "left about 10 years ago", which would have been 1985, when Vikernes was 11 or 12.

The Encyclopedia of White Power and historian Nicholas Goodrick-Clarke have both alleged that Vikernes was part of the neo-Nazi skinhead culture as an adolescent. When asked in the Lords of Chaos interview whether he hung out with skinheads in Bergen, Vikernes said that "there were no skinheads in Bergen".