Isengard was a Norwegian musical project by Darkthrone drummer Fenriz.
The name Isengard comes from J.R.R. Tolkien's book The Lord of the Rings and is where the wizard Saruman resided.
The logo comes from the role-playing game MERS, it represents the vampire Thuringwethil ('Woman of the Secret Shadow'),
a character from Tolkien's book The Silmarillion
Since Fenriz gave up singing on Darkthrone but wanted to continue singing,
and some of his influences were not compatible with Darkthrone's style, he realized both with Isengard.