Question: When was the band that put out Under the Sign of Hell formed?

full_context: Document 1: True Norwegian Black Metal – Live in Grieghallen: True Norwegian Black Metal – Live in Grieghallen is Gorgoroth's first full-length live album, released by Regain Records. It was recorded live in the studio at Grieghallen Lydstudio in Bergen and Threeman Recordings in Stockholm. The songs on the album represented the most commonly played songs in Gorgoroth's live set. The cover design by Magnus Wohlfart was radically different from the previous three full-length albums, being more reminiscent of the cover of the album "Under the Sign of Hell" (1997). Most of the album was recorded before the departure of vocalist Gaahl and bass guitarist King ov Hell, who had intended on using the band's name and assets. The bass guitar for this album (originally performed by King ov Hell) was later re-recorded by guitarist and band founder Infernus. Infernus dedicated the album to the late Jon Nödtveidt of Dissection.
Document 2: Gorgoroth name dispute: The Gorgoroth name dispute refers to a legal dispute between musicians from Norwegian black metal band Gorgoroth over who had ownership of the band's name, which was derived from J. R. R. Tolkien's legendarium. The parties to the dispute were band founder Infernus (Roger Tiegs) and members Gaahl (Kristian Espedal) and King ov Hell (Tom Cato Visnes). It began in October 2007, when it was announced that Gaahl and King had decided to part ways with Infernus, although the former two claimed to have "fired" the latter. The dispute was concluded in March 2009 when a court verdict recognising Infernus as the legitimate user of the name was announced, and the outcome of the dispute also established a precedent in Norway for subsequent similar disputes.
Document 3: Under the Sign of Hell: Under the Sign of Hell is the third studio album by Norwegian black metal band Gorgoroth. Recorded in 1996 and released in 1997, it was the first album to feature Ares on bass (on one track) and the only one to feature Grim on drums.
Document 4: A Sorcery Written in Blood: A Sorcery Written in Blood was the first demo released by Norwegian black metal band Gorgoroth. The title of the demo was taken from the lyrics of the song "The Return of Darkness and Evil" by the band Bathory. The demo was released in 1993 as a limited edition hand-numbered cassette. A 7" vinyl bootleg also existed; however, there were no official reissues. Due to the Satanic imagery used on the demo cover, the newspaper "Firda" in Førde in Sogn og Fjordane, Norway, ran a front-page story on the demo and Gorgoroth on 7 January 1994. The demo led to the band landing a record deal with French record label Embassy Productions. The track "Sexual Bloodgargling" was an early version of the song "Ritual", re-recorded for Gorgoroth's first album "Pentagram".
Document 5: Blizzard Beasts: Blizzard Beasts is the fourth studio album by Norwegian black metal band Immortal. It was released on 20 March 1997 through Osmose Productions. It is the last Immortal album to feature founding member Demonaz Doom Occulta on guitar, and the first to feature Horgh on drums. Demonaz was later diagnosed with acute tendinitis which prevented him from playing guitar at the required speed for Immortal's music. Stylistically, "Blizzard Beasts" has primarily songs that are less than three minutes long, contrasting with Immortal's usual longer song lengths.
Document 6: Horrors of Hell: Horrors of Hell is a compilation album by the American death metal band Vital Remains, consisting of early demo recordings. It was released in 2006 by Century Media. All tracks are remastered, and the album is limited to 5000 copies.
Document 7: Gorgoroth: Gorgoroth is a Norwegian black metal band based in Bergen. It was formed in 1992 by guitarist Infernus, who is also the only original member remaining, and the band have since released nine studio albums. Gorgoroth are a Satanic band and have drawn controversy due to some of their concerts, which have featured impaled sheep heads and mock crucifixions. The band is named after the dead plateau of darkness in the land of Mordor from J. R. R. Tolkien's fantasy novel "The Lord of the Rings".
Document 8: God Seed: God Seed was a Norwegian black metal band based in Bergen, Norway. Former Gorgoroth members Gaahl and King ov Hell adopted the name in March 2009 following the ending of the Gorgoroth name dispute. After performing a few gigs as God Seed, vocalist Gaahl left the band in July 2009 and it was put on hold. King finished the music for God Seed's first album, with vocalist Shagrath, and released it under the name Ov Hell. Gaahl re-joined God Seed in 2012. In January that year they released the live album "Live at Wacken", and in October they released their first studio album, "I Begin".
Document 9: Incipit Satan: Incipit Satan is the fifth full-length album by Norwegian black metal band Gorgoroth. It was released on 7 February 2000 by Nuclear Blast, and reissued in 2006 by Back on Black Records. "Incipit Satan" was the first album with King ov Hell as bassist, the last album to feature Tormentor on guitar and the only one with Sjt. Erichsen on drums. The band members dedicated the album to their deceased friend and former bandmate Erik Brødreskift (a.k.a. "Grim").
Document 10: Tormentor (musician): Tormentor (* 05.06.1972) is a black metal musician who is best known for his work as guitarist with the Norwegian black metal band Gorgoroth.
Document 11: Infernus: Roger Tiegs (born on 18 June 1972), better known by his stage name, Infernus, is a Norwegian black metal musician and Satanist. He is the sole founding member and chief ideologist of the Norwegian black metal band Gorgoroth, which was formed in 1992, as well as the founder and head of Forces of Satan Records. He is mainly a guitarist, but has also participated as bassist, drummer and vocalist on several recordings released both by Gorgoroth and other bands.
Document 12: Ad Majorem Sathanas Gloriam: Ad Majorem Sathanas Gloriam is the seventh studio album by Norwegian black metal band Gorgoroth. It was released on 19 June 2006 by Regain Records. This was the only Gorgoroth album on which all of the lyrics and music were written by Gaahl and King ov Hell, and was the last to feature both members It also marked the return of drummer Frost and was the last Gorgoroth album that he appeared on. It was nominated for Norway's 2006 Spellemann award in the "Metal" category. It is the first Gorgoroth album with no Norwegian lyrics.
Document 13: 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.
Document 14: King ov Hell: Tom Cato Visnes (born November 27, 1974), better known as King ov Hell or simply King, is a Norwegian musician. He is best known as the former bassist of black metal band Gorgoroth, but he is also the co-founder of Ov Hell, God Seed, Jotunspor, Audrey Horne, Sahg, I and Temple of the Black Moon.
Document 15: In Sorte Diaboli: In Sorte Diaboli (Latin for "In league with the devil") is the eighth studio album by Norwegian symphonic black metal band Dimmu Borgir, released in 2007. It is the band's first concept album. A site on the Nuclear Blast website was created for "In Sorte Diaboli", in which a new promotional photo can be seen and an audio sample can be heard. This would be the last album by Dimmu Borgir to feature ICS Vortex, Hellhammer and Mustis.
ground_truth: 1992