ROSSOMAHAAR first emerged with the 1998 demo cassette 'Grotesque', comprising recordings dating back to 1995 when the band operated as a duo of Lazar and drummer Vlad. Main man Lazar is also a member of ambient dark wave project NARGATROND and Moscow Doom Metal act STONEHENGE. Although the 'Grotesque' session was completed as a solo project of Lazar, bass player Baalseguothsarius of STONEHENGE became involved in ROSSOMAHAAR during 1998. Other members involved during this same year included guitarist Ixxaander of TALES OF DARKNORD and DER GERWELT repute, STONEHENGE bassist Kniaz' along with drummer Sigizmund of MENTAL HOME.

The 2000 album 'Imperium Tenebraum' sees lyrics from Kai Mathias Stahlhammer of NARGATROND. Originally released by the domestic CDM label ROSSOMAHAAR secured a deal with the American Rated X concern for releases outside of Russia.

ROSSOMAHAAR conducted extensive touring in Russia throughout 2000 after which both Sigizmund and Ixxaander bailed out. Yanarrdakh took the drum position in the summer of 2002. The band recorded a cover of MANOWAR's 'Gloves Of Metal' for a tribute album during 2002. Whilst the 2003 album 'Regnum Somni' proudly boasted "no keyboards" it did see contributions in the studio from trombonist Vladimir and alt sax player Ilyia Gum from Ska-Core band NEOCONDITION.