Although the band has been a trio for most of its history, several albums have been recorded as a duo, with varying combinations of Abbath, Demonaz, and Horgh.

The music on their early demo recordings was death metal,[6] with lyrics influenced by Morbid Angel and Possessed.

This was followed by their debut album Diabolical Fullmoon Mysticism in 1992, which maintained the raw black metal sound developed the previous year.

Their second full-length album Pure Holocaust was released in 1993 and featured a relatively more polished production than their debut, with ambitious songs played at breakneck speeds, and grandiose lyrics based on evil and darkness.

Battles in the North, released in 1995, picks up where its predecessor left off, featuring more extreme tempos and lyrics about coldness and winter landscapes.

In 1995, the band released two video clips directed by British artist David Palser, entitled Masters of Nebulah Frost, through Osmose Productions.

They featured many bizarrely-shot images of frozen landscapes and vast forests with the band performing two songs from the album Battles in the North, "Grim and Frostbitten Kingdoms" and "Blashyrkh (Mighty Ravendark)", on a Norwegian mountainside.

The video for "Grim and Frostbitten Kingdoms" features Mayhem drummer, Hellhammer (Jan Axel Blomberg).

Blizzard Beasts released in 1997 introduced technical thrash elements with shorter more focused songs, though it contained the epic "Mountains of Might" and continued the lyrical themes of cold and winter.

Apart from the two core members, Abbath and Demonaz, Immortal did not find a stable lineup until 1996 when drummer Horgh joined the band and is credited on the album Blizzard Beasts.

A major turning point for the band was in 1997 when Demonaz suffered acute tendinitis in his arm and was unable to continue playing, and Abbath took over for guitar.

During the tours for this album, the band recruited Iscariah to stand in for bass duties, and made him a full-time member.

[11] In early June 2006, German magazine Rock Hard reported that Abbath, Demonaz and Horgh had decided to resurrect Immortal and start touring again in 2007.

[2] On 8 January 2018, the band posted via Facebook an update on Immortal's upcoming ninth full-length, stating "We have put a massive amount of energy into this, and wanted to deliver our absolutely best.

They created Blashyrkh to mirror those feelings, basing it on Norway, including "winter landscapes", "the woods, the mountains, the darkness, the fog", and "glacial valleys".

[15] When writing lyrics, the band's lyricist Demonaz often takes long walks in the Norwegian countryside near his hometown of Bergen for inspiration.

Unlike many early black metal bands, Immortal does not have satanic-themed lyrics,[26] opting instead for basing the genre's inherent concepts of darkness and evil in the fantasy setting of Blashyrkh.