Nokturnal Mortum is a Ukrainian black metal band from Kharkiv.
Nokturnal Mortum started as death metal band Suppuration in 1991, then turned to black metal and changed name to Crystalline Darkness but "had to change the name back in 1993/94 to Nocturnal Mortum because there already existed a band with that name in western underground." Then the band "changed the letter so that we wouldn't find a band with the same name again like it was the case with Crystaline Darkness." Nokturnal Mortum gained their first Western recognition with the release of their album Goat Horns, their second full length album, notable for having two keyboardists play on the album, often on the same song, and for mixing traditional Ukrainian music with black metal. As traditional instrumentation gained in significance and the lyrical concept moved away from black metal's patterns, the newer releases are classified as pagan metal.
The band's first albums were released through The End Records and (as licence pressings) through Nuclear Blast, but the label and band separated after releasing the album NeChrist and a re-release of the "Lunar Poetry" demo due to a disagreement.