See also
Arcturus.
Mortem formed in 1987 with Hellhammer on drums, Steinar Johnson on guitar and keyboard and Marius Wold for vocals. Emperor's Samoth also played bass on their one and only release "Slow Death". In a few years they became Arcturus and with that name have become known all over the world.
Mortem was one of the first black metal bands in Norway. Darkthrone's Fenriz remembers Mortem and Mayhem being the only other black metal and blackened death metal bands that they had contact with in the late 80's and early 90's. Not too much later the whole scene would break out, but Mortem deserves some recognition in the Norwegian Black Metal scene.
Discography
Slow Death (ep/demo)