Locrian was formed in late 2005 by André Foisy and Terence Hannum, who had previously played together in Unlucky Atlas. Foisy is originally from Northern New York, while Hannum is from Florida. The group has released over 20 recordings in their relatively short lifespan, on labels such as Small Doses, Bloodlust!, and At War With False Noise, as well as on the group's private label Land of Decay.

In 2009, the band released their first studio album, Drenched Lands. The album was met with acclaim from the Chicago Tribune, the Chicago Reader, and Rock-A-Rolla magazine. Locrian followed its release with a U.S. tour, including a special Pitchfork Media sponsored Show No Mercy show in New York City, NY. Their 2009 Rain Of Ashes release features two 30-minute long tracks recorded live at the University Of Maryland's radio station WMUC. A second album, Territories, was released in 2010, which took the band in a more rock-oriented direction, featuring guest appearances from members of Nachtmystium, Bloodyminded, Yakuza and Velnias, and this was followed by a third, The Crystal World, later the same year, the title coming from a J. G. Ballard novel. The Crystal World features a new member, percussionist Steven Hess.