Question: Abbath was formed by the former guitarist of the black metal band from what Norwegian city?

Context paragraphs:
The Older Ones: The Older Ones is the first compilation album by Norwegian blackened death metal band Old Funeral, which was made up by key players in the Norwegian black metal scene, including bassist/vocalist Olve "Abbath" Eikemo (Immortal), guitarist Harald "Demonaz" Nævdal (Immortal) and guitarist Kristian "Varg" Vikernes (Burzum).  By the time this album was released, the members had already gone their separate ways, with Immortal a going concern for Abbath and Varg in jail.

Satyricon (band): Satyricon is a Norwegian black metal band, formed in 1991 in Oslo.  Satyr and Frost have been the band's core members since 1993.  The band's first three albums typify the Norwegian black metal style.  Since its fourth album in 1999, the band has strayed from this style and included elements of traditional heavy metal in their sound.  Satyricon was the first Norwegian black metal band to join a multi-national record label (EMI).

Ivar Bjørnson: Ivar Bjørnson (born November 27, 1977 in Etne) is a Norwegian composer/guitarist for the progressive black/viking metal band Enslaved.  He is, along with Grutle Kjellson, one of only two founding members left in the current line-up, being only 13 years old at the time of the band's formation in 1991.  Bjørnson and Grutle Kjellson performed in a death metal band called Phobia in 1989.  The two decided that they wanted to form a new band in a more black metal style, and after discovering their shared fascination with Norse mythology, this set the groundwork for Enslaved.  Beyond his duties on guitar, he writes almost all of the music for Enslaved as well as much of the lyrics.  He has said that "When we started Enslaved we wanted to have the same level of commitment to something spiritual as our contemporaries in black metal [have with] the Satanic side.  The dark destructive part of black metal didn't seem right because we didn't have any commitment to any Satanic ideology."  He contributed keyboard/synth work to Borknagar's first three albums and synth/piano work on the Gorgoroth albums "Incipit Satan" and "Destroyer" under the name "Daimonion"; and also produced the first demo from black metal band Orcustus.

ICS Vortex: Simen Hestnæs, also known as I.C.S. Vortex or simply Vortex, is a Norwegian musician.  He is the vocalist of the similarly named band ICS Vortex, the avant-garde metal band Arcturus, and the doom metal band Lamented Souls.  He is also the vocalist and bass guitarist to the progressive black metal band Borknagar, and the former bass guitarist and backing vocalist for the Norwegian symphonic black metal band Dimmu Borgir.

Abbath (band): Abbath (stylized as ABBATH) is a black metal band formed in 2015 by former Immortal guitarist and vocalist Abbath Doom Occulta after departing from Immortal earlier in 2015.  The band released their first album, "Abbath", on January 22, 2016, and played live for the first time at Tuska Open Air 2015.

Darkthrone: Darkthrone is a Norwegian heavy metal band.  It formed in 1986 as a death metal band under the name Black Death.  In 1991, the band embraced a black metal style influenced by Bathory and Celtic Frost and became one of the leading bands in the Norwegian black metal scene.  Their first three black metal albums—"A Blaze in the Northern Sky", "Under a Funeral Moon" and "Transilvanian Hunger" (sometimes dubbed the "Unholy Trinity") — are considered the peak of the band's career and to be among the most influential albums in the genre.  For most of this time, Darkthrone has been a duo of Nocturno Culto and Fenriz, who have sought to remain outside the music mainstream.  Since 2006, their work has strayed from the traditional black metal style and incorporated more elements of traditional heavy metal, speed metal and punk rock, being likened to Motörhead.

Olve Eikemo: Olve Eikemo (born 27 June 1973), better known by his stage name Abbath Doom Occulta or simply Abbath, is a Norwegian musician best known as a founding member of the black metal band Immortal.  Before founding Immortal, Abbath performed with Old Funeral alongside future Immortal member Demonaz.  While working with Old Funeral, he also joined Demonaz's band Amputation which later became Immortal.  He also plays bass in Demonaz's eponymous project.

Immortal (band): Immortal is a black metal band from Bergen, Norway, founded in 1991 by frontman and bassist Abbath Doom Occulta (Olve Eikemo) and guitarist Demonaz Doom Occulta (Harald Nævdal).  The pair worked with various drummers (including Grim, Armagedda and Hellhammer), and were later joined by current drummer Horgh (Reidar Horghagen) in 1996.

Strid (band): Strid is a Norwegian black metal band that was originally known as "Malfeitor" from 1991 to 1992.  After releasing two demos - "Malfeitor" (in 1991) and "Pandemonium" (in 1992), they changed their name to "Battle" and there were some line up changes at the time.  In the year of 1992 the band released the "End of Life" demo.  The demo contains only one song which is around 11 minutes.  The line up at the time of recording the demo was: Storm - on bass and vocals, Lars Fredrik Bergstrøm - on guitars and Jardar - on drums.  The guitars were written by Lars Fredrik Bergstrøm (1974 - 2014).  In 1993 the band changed the name to "Strid" which means "Battle" in Norwegian.  That same year, Strid re-released their "End of Life" demo under their new name, through the German label "Malicious Records".  After releasing the "End of life" demo, Lars Fredrik Bergstrøm left the band and was replaced by Ravn Harjar.  Through the years between 1993 and 1995, the band writes and records the self-titled EP which was released through Malicious Records and contains only two songs - "Det hviskes blant sorte vinder" which means "It Is Whispered Amid the Black Winds" in Norwegian and "Nattevandring" which means "Nightwandering" in Norwegian.  The music style and sound of this demo is more ambient/atmospheric black metal oriented.  Mainly because of this release, the band is commonly recognised as the creators of depressive black metal along with some other bands from the second wave of black metal music.  At this time the band line up contains: Ravn Harjar - on guitars, Storm - on bass and vocals and Jardar - on drums.  After the releasing of the self-titled EP, there was no any official releases by the band.  There are also bootleg releases that came out through the years like the CD from 2005 by Ars Mysteriorum and LP, each featuring both "End of Life" and the self - titled EP tracks.  In the year of 2001 the original former member of "Malfeitor/Battle/Strid", bass player and vocalist - Storm committed suicide.  In the year of 2007, the Greek label Kyrck Productions & Armour re-released all the previous material released by the band from the past which contains all "Malfeitor/Battle/Strid" material.  Somewhere between 2009 and 2010 there was a reunion of the band with old members including Vicotnik (Dødheimsgard, ex-Aphrodisiac, ex-Ved Buens Ende, ex-Manes, ex-Code, ex-Naer Mataron, ex-Endwarfment).  Another member that was part of the reunion was Lars Fredrik Bergstrøm - the main composer of the "End of Life" track.  In 2014 Lars Fredrik Bergstrøm died.  At this time the band line up contains Ravn Harjar - on guitars and vocals, Vicotnik - on bass and Sigmund (ex-Inflabitan, ex-Dødheimsgard) - on guitars.  In January 2015, Ravn Harjar wrote a statement on the official Strid Facebook page that in the autumn of the year 2015 the band will start recording their first full-length album which will be titled "Endetid".  That means "End of times" in Norwegian.

Between Two Worlds (I album): Between Two Worlds is the debut album by Norwegian black metal supergroup I.  The album was recorded at the Lydriket Studio and later mixed by Peter Tägtgren at the Abyss studio.  The album showcases Abbath's straightforward metal style rather than his black metal style.  The album displays a clear influence from classic metal bands, which although present in Abbath's primary band Immortal, is here the sole focus of the music.  A limited edition digipack was released, which includes three bonus tracks.  A limited edition metal box was also released, also featuring the three bonus tracks, and was limited to 1000 copies.

Supporting paragraphs: Abbath (band) Immortal (band)
Answer: Bergen