According to HM magazine, the progressive elements on the debut album, Martyrium, were possibly ahead of their time in the Norwegian extreme metal scene.

The original vocalist Kjetil Molnes (Martyr) and drummer Svein Sander (Armoth) left the band around 2000, and the members of a fellow Norwegian black metal group, Vaakevandring, joined Antestor.

The reputable Norwegian extreme metal drummer Jan Axel Blomberg (Hellhammer) played session drums for their 2005 album The Forsaken and Det tapte liv EP.

In 1990, the band was formed under the name Crush Evil by Lars Stokstad, Kjetil Molnes, Øyvind Hope and Erling Jørgensen in Jessheim, Norway.

For example, during the early 1990s, Bård Faust of Emperor brought up the subject when he discussed with Euronymous, guitarist/vocalist from the seminal black metal band Mayhem, in his zine Orcustus about the Norwegian scene.

[8] On June 3, 1994 Antestor appeared on a local television program called "BootlegTV" where youth could practice and experience recording and video production.

The promo-CD caught the interest of British Cacophonous Records, one of the biggest labels with experience in the black metal style and helped established groups such as Cradle of Filth and Dimmu Borgir start their career.

Cacophonous being a secular label releasing material by a band that held Christian beliefs generated some interest in the metal scene.

The album relies on hypnotic, cold atmosphere and showcases influences from Norwegian folk music, which led some to label Antestor as Viking metal.

Ann-Mari Edvardsen, who has sung in the Norwegian gothic metal group The Third and the Mortal, joined the band as a female vocalist.

[18] For the first time in their career, Antestor began using the infamous corpse paint masks as a part of their live shows and overall image.

Antestor toured the United States with Extol that year, playing small venues and finally performing at Cornerstone Festival.

[15] Over the next several years, the band remained somewhat quiet; they did not release any more albums until 2003, when they re-released their two earliest demos on one CD, titling it The Defeat of Satan.

Det tapte liv concentrated less on the black metal aspects of Antestor's style, instead focusing more on instrumental songs.

Examples of performances the group have made in 2000s include the concerts at Bobfest in 2000 in Stockholm[22] and 2004 in Linköping,[23] and at the Nordic Fest 2004 in Oslo.

[29] After the show, the band posted a public statement about the incident, thanking their fans for coming despite the risks involved, and blessing the radicals: "We are proud to call you our brothers and sisters in Christ.

"[30] In a newspaper interview with the Norwegian Christian newspaper Dagen two days following the band's safe return to Norway, bassist Erik Normann Aanonsen said that he had prepared himself for the worst-case scenario that the tour could end in death, and he reiterates the band's gratitude to the aggressive Brazilian Satanists stating: "We're now twice as big in Brazil as we were before we went there.

On that album the band showcased screaming vocals, tremolo guitar riffs and drum passages with increased speed typical for the black metal genre.

Keyboard is also in a central role, which for the typical black metal is used to perform epic interludes and dominates the soundscapes.

Antestor's lyrical themes include hope and despair, but also deal with the personal Christian faith of the band members.

On this album, only part of the lyrics are listed in the booklet; words directly referring to Jesus Christ and God were omitted.

An example (in the Norwegian language): Hvordan Skal Jeg Kunne LeveMin Sjel Så Høyt ForhattSorg Er Hva Jeg FølerAlt Så Ensomt Og Forlatt(Antestor: The Return of the Black Death, song 4: "Sorg"; Cacophonous, 1998)How Should I LiveMy Soul So Highly HatedSorrow Is What I FeelEverything Is So Deserted And Abandoned(free translation)Another song that is also a dark, but this takes on Christian theme, is "Ancient Prophecy".

Antestor process in their lyrics also topics such as suicide, doubts about the certainty of salvation, and longing death, all of which are rare themes for a Christian band, however common to several subdivisions of Black metal, such as DSBM.

An example from the text "Betrayed" from the album The Forsaken: Will Suicide Break The Ring of CurseOr Is There Just Another Hell Waiting Out ThereWill Suicide Break The Ring of CurseTomorrow I'll Be Gone, So Don't Look For Me(Antestor: The Forsaken, song 6: "Betrayed"; Endtime Productions, 2005)Antestor are one of the few bands in the Christian metal scene who use corpse paint in their appearances and on photos.

Sometimes the group uses art blood, as known for the session bassist Ravn Furfjord's (Frosthardr) appearance at the Bobfest 2004 concert.

"[19] According to Vrede in an interview with Intense Radio on December 13, 2007, "by various sources, The Return of the Black Death has sold over 10,000 copies and still keeps selling.

Michael Bryzak writes in the liner notes of The Defeat of Satan / Despair that, although the first album was not officially released until 2000, "Martyrium was rightfully considered a cult classic."

Bryzak writes that "standing up for their faith in Life and Hope, Antestor received serious death threats during this time from some of the major bands and key players of the scene."

'"[17] In the liner notes of Martyrium, Antestor corresponds in a slightly bitter tone: "For those of you who despised us, disbelieved in us and misplaced your anger upon us, may God have mercy on your poor souls!"

"[32] Jamie Lee Rake of HM Magazine wrote of the Endtime Productions re-release of Martyrium, wondering if the progressive elements of the album made the band unnoticed innovators in the early Norwegian extreme metal scene: Throughout Martyrium's nine tracks, there are touches of more progressive deathiness: piano and other keyboards, those nearly operatic female vocals, etc.