Covariance is a one man band started in 1999 by Matthias (also in Deathwing and Archenterum).
"Chapter I: Enslaved by Hate" was the first demo CD of black metal music with atmospherical elements.
The second creation was "The Dark War", recorded and mixed in 2004/2005 yet remained unreleased. And the project was on hold for a few years.
In october 2013, "The Dark War" was finally out on Jamendo. The music is a mix of black metal and more dark ambiant songs.
In the future, Covariance will be working on really differents songs and experimentations yet keeping its roots in death metal and black metal.