CMX (Cloaca Maxima) was founded in 1985 by vocalist / bassist Aki Yrjänä, Pekka Kanniainen and Kimmo Suomalainen. The first EP, 'Johannes Kastaja' ("John the Baptist"), was released by the minor label P-Tuotanto. Switching to the Bad Vugum label, CMX published the debut album 'Kolmikärki' ("Trident") in 1990. Second album Veljeskunta ("The Brotherhood") emerged in 1991. That year the group underwent a succession of line-up changes, Yrjänä finally settling on a stable cast of guitarists Janne Halmkrona, also a member of BLACK SABBATH covers band SAPATTIVUOSI, and Timo Rasio with Pekka Kanniainen on drums.

CMX switched labels to the major EMI concern for third record 'Aurinko' ("The Sun"). 'Aura' followed in 1995, scoring the band a top 5 hit in the national Finnish album charts. Successive releases included 1995's 'Rautakantele' ("The Iron Kantele") and 1996's Electro flavoured 'Discopolis', the band's first record to achieve gold sales status. In late 1997 the 'Cloaca Maxima' compilation comprised the band's hits, B-sides and rarities. Pekka Kanniainen then resigned, his position on drums being taken by Tuomas Peippo. In 1999 CMX announced they were to stop playing live, performing their final concert that July at 'Ilosaarirock' in Joensuu. Nevertheless, a new album in 2000, the highly progressive entitled 'Dinosaurus Stereophonicus' hit the no. 1 spot in the charts.