|In 1990, the band was formed under the name "Crush Evil" by Lars Stokstad, Kjetil Molnes, Øyvind Hope and Erling Jørgensen in Jessheim, Norway. Paul W joined them as a drummer later on. Back then, the band's music style was a mixture of death metal, doom metal, and thrash metal. In 1991, they recorded and released their first demo, The Defeat of Satan, which contains three songs and an outro. The band is Christian and over the course of their career have received death threats because of this.
In 1993, Vegard Undal joined the band as a bassist and Svein Sander became their drummer. During that time, they changed the name Crush Evil to Antestor, which is (Latin for "call to witness" or "testify"). Despair was their first self-released demo, and was released under the band name Antestor. The demo starts with an intro and ends with a cover of an old Norwegian hymn, called "Jesus, Jesus, Ver Du Hjå Meg" (Jesus, Jesus, Be With Me). Strawberry Records pressed 600 copies of the recording.
In 1994, Antestor recorded their first full-length album titled Martyrium. Arctic Serenades Records was originally supposed to release that album, but because of unknown reasons that never happened, and the band tried to get another label to release the album. In an interview, the drummer Armoth said: "...we were in contact with a label called Morphine Records. But that was about signing a deal for the Martyrium album. But we never signed a contract but that guy, Burrito, made several promotapes and sold every bit of it illegally 'cause he didn't have a contract." However, the tape copies circulated in up to fifth generation copies and their audience grew fast. Martyrium was the last album that emphasized on their death/doom direction.
On June 3, 1994, Antestor appeared on a local television program called "BootlegTV" where youth could practice and experience recording and video production. Usually local bands from Oslo played on that program which was broadcasted on the television station TVNorge. During the course of this program, Antestor played five songs from Martyrium. On June 6, 1995, Antestor was featured on the Norwegian weekly newspaper Morgenbladet's article about the phenomenon of Christian black metal, surrounding the black metal parody controversy of the Australian unblack metal group Horde's 1994 album Hellig Usvart. In the article, vocalist Kjetil Molnes explains the band's stance on if a Christian band can play black metal: "We identify ourselves as black metal as a music style, not black metal as an ideology or belief."
In 1997, Antestor recorded a promotional CD titled Kongsblod. 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 signed a record deal for 2 albums with Antestor. In 1998, Cacophonous released Kongsblod under a different name, The Return of the Black Death, and changed the original cover art of a famous Norwegian painting to artwork by Joe Petagno, a well-known American heavy metal cover art creator.
The Return of the Black Death was mostly well received by both Christian and non-Christian black metal fans and critics. For example, the British metal magazines Kerrang! and Terrorizer both gave the album 4 points out of 5. Musically, The Return of the Black Death is a mixture of black metal and doom metal. The album relies on hypnotic, cold atmosphere and showcases influences from Norwegian folk music, which led some to label Antestor as Viking metal. Unlike previously, around this time the band themselves said they felt uncertain whether a Christian band can play black metal, because the movement was still strongly associated with Satanism.
In 2000, Antestor was signed by Endtime Productions, a metal record label that also helped to start the career of the Norwegian metal band Extol. The original vocalist Kjetil Molnes (Martyr) left Antestor. However, the breakup of another Christian metal band in Norway, Vaakevandring, led to several former Vaakevandring members joining Antestor. Namely, Ronny Hansen, adopting the new moniker Vrede, became Antestor's new vocalist, and Morten Sigmund Mageroy (known in Antestor as Sygmoon) stepped in as the new keyboardist. Ann-Mari Edvardsen, who has sung in the Norwegian gothic metal group The Third And The Mortal, joined the band as a female vocalist. 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.
In 2000, Endtime Productions released Martyrium with cover art done by the reputive Swedish metal music cover artist Kristian Wåhlin. Antestor toured the United States with Extol that year, playing small venues and finally performing at Cornerstone Festival. 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. The drummer, Svein Sander (in Antestor, Armoth), left the band during this time, and Antestor would not find a new full-time drummer for several more years.
In 2004, Antestor changed their style into a more modern black metal, and released their first set of new songs since "The Return of the Black Death" in an EP called Det Tapte Liv (The Lost Life). Det Tapte Liv concentrated less on the black metal aspects of Antestor's style, instead focusing more on instrumental songs. However, it hinted at what the band was preparing for their 2005 full-length, The Forsaken. The cover arts for both releases were once again done by Kristian Wåhlin, and the cover for the EP depicts the Borgund stave church. Hellhammer played all drums on both of these releases. In an interview with the Russian metal site Metal Library on January 7, 2007, Blomberg was asked what did his Mayhem colleagues and record company think about his participation in Antestor, and he said: "To be honest, it was a big 'fuck off!' to them all. I will repeat again that I decide what I do and I play not only in black metal groups." The band also asked Hellhammer to play live for them, but Blomberg refused. Hellhammer also went to state: "In my opinion, black metal today is just music. I will tell you that neither I nor other members of Mayhem never really were against religion or something else. We are primarily interested in music."
New drummer Tony Kirkemo joined the band later in 2005 as live session drummer. The band played live shows rarely and only at explicitly Christian music festivals. Examples of performances the group have made in 2000s include the concerts at Bobfest in 2000 in Stockholm and 2004 in Linköping, and at the Nordic Fest 2004 in Oslo.
Some of the members still play in the black metal band Vaakevandring, who played a reunion concert in 2007 together with Antestor at the Endtime Festival held at the end of March 2007 in Halmstad. Antestor performed the concert with numerous session musicians. In this concert the band announced that this is their last live show. In a message in the forum of Endtime Productions, and a substantially identical bulletin on the band's MySpace, Lars Stokstad stated that the reasons for the decision were that the last 2 and half years the only consistent members of the band have been Vrede and Vemod, and they have constantly had problems finding musicians willing to commit to Antestor. After three years of hiatus on January 29, 2010, the band launched an official Facebook page. Later they announced new members: Bassist Thor Georg Buer (Grave Declaration), guitarist Robert Bordevik (Grievance, Vardøger), drummer Jo Henning Børven (Morgenroede) and keyboardist Nickolas Main Henriksen (Aspera, Desdemon). With this line-up, the band played a stage show at Nordic Fest 2010 in Oslo. On November 4, 2010 they announced signing to Bombworks Records to record a new album and an EP. After some line-up changes in mid-2011, Erik Normann Aanonsen (Moddi) joined on bass while Thor Georg switched to guitar, and the show at the Norwegian Seaside Festival was with that line-up. The album has been recorded and will be mixed and mastered in Sweden. Guitarist Thor also left the band to focus on his college education, but stated he may return if the opportunity arises.