Isengard has been played on NTS in shows including A Fist in the Face of God presents: Midnite Madness, featured first on 12 November 2014. Songs played include Naglfar, Thy Gruesome Death and Vinterskugge.

Isengard was a pagan black metal solo project of Fenriz, famous for being the drummer of Darkthrone, created in 1989.

The person/creature in Isengard's logo was taken from an old Lord of the Rings RPG called Middle-Earth Role Playing. The original illustration represents Thuringwethil, the vampire from Tolkien's book The Silmarillion.

Vinterskugge is a compilation of three demos recorded before the full-length album Høstmørke was recorded.

In 2016, Peaceville Records issued a two-song 7" entitled "Traditional Doom Cult". Its A-side, "The Light", was recorded in 1989 whereas the B-side "The Fright" was recorded in the early 1990s.

It was announced that a third Isengard album entitled "Vårjevndøgn" would be released in October 2020, consisting of unreleased recordings from 1989-1993.