CMX was founded on Good Friday 1985 in Tornio, Finland by A. W. Yrjänä (18 at the time) and Pekka Kanniainen. The band's original name, Cloaca Maxima, Latin for the "Greatest Sewer", was taken from a footnote of H. P. Blavatsky's book Isis Unveiled. Over the next six months Kanniainen became the drummer, Yrjänä the bassist and singer, and Kimmo Suomalainen the guitarist. The band played mainly fast hardcore punk with the vocals sung in English; the language, however, soon changed into Finnish. The band shortened its name to CMX in 1986.