YYRKOON debuted in 1996 with the demo 'Oath, Obscure, Occult'. During 2001 bassist Kristofer Lorent formed the side project BURGUL TORKHAIN for album 'The Adventures Of Burgul Torkhaïn', recorded with GRONIBARD and BELENOS drummer Gilles Delecroix sessioning and LUCRETIA's Pat Frescura on guitar. Two tracks originally intended for YYRKOON, 'Under The Green Moon' and 'Amothep', would make the final running order. Meantime, as a backdrop to BURGUL TORKHAIN's progress Lorent had exited YYRKOON to join DEMENTIA.

During April of 2004 YYRKOON signed a new deal with Osmose Productions for their third album 'Occult Medicine', recorded and mixed at Hansen studios in Ribe, Denmark. Drummer Laurent Harrouart left for "personal reasons" in June.

European shows for January 2005 found YYRKOON in union with IMPALED NAZARENE and PHAZM. Manning the drums would be drummer Dirk Verbeuren, a much travelled scene veteran citing credits with SCARVE, ABORTED, STENVAL, MORTUARY, ANAON, ETERNAL GRAY and SOILWORK amongst many others. The group re-introduced Laurent Harrouart on the drums in March. In June Stephane Souteyrand joined Belgian act ABORTED.

YYRKOON entered Hansen studios in Ribe, Denmark during November to craft the 'Unearthly Opera' album. KING DIAMOND guitarist Andy LaRocque cut a guest solo on the song 'Horror From The Sea'.

In February 2007, after completing a run of dates partnered with NILE, it seemed YYRKOON was on the verge of breaking up when frontman Stéphane Souteryrand issued a statement saying "I have to admit that I've lost my motivation for YYRKOON. I cannot continue to lie to myself; I need a pause to reconsider my position in the band.". YYRKOON duly cancelled all scheduled concerts.