A Joensuu Doom / Death Metal band established during 1988, PHLEGETHON is named from Greek mythology, being one of the five principal rivers of fire in the realms of Hades. Initially the band was formed as a trio of guitarists Teemu Hannonen and Juha Tykkyläinen with Lasse Pyykkö on drums. A demo cassette, recorded without bass and entitled 'Visio Dei Beatifica', was issued in October 1989. Having drafted bassist Jussi Nyblom a second session 'Neutral Forest', featuring Jukka Timonen on keyboards, followed in June 1990. In 1991 PHLEGETHON tracks recorded between February, with Hannonen on lead vocals, and re-tracked in May with Jussi Nyblom now as vocalist, at Mix Man Studio were put out by Swiss label Witchhunt Records as the 'Fresco Lungs' EP. This was re-issued on CD format in 1992, adding two newly recorded tracks 'Stone Me' and 'Without Tea Waters'.

PHLEGETHON folded in 1992 but reformed three years later. A three song demo cassette, simply titled 'Promo 1995', resulted that November. However, Saku Hurskainen recorded all lead guitar parts. Drummer Lasse Pyykkö was later to be found as a member of SARNATH. In 2003 Pyykkö forged NERLICH in union with vocalist / bassist Miikka Merikallio and guitarist Jarno Nurmi.

Lasse Pyykkö, Juha Tykkyläinen and Saku Hurskainen refounded PHLEGETHON to record the 2006 demo 'Totem Within'. The first brace of demos saw reissue as the 2006 album 'Visions From The Forestside'. A February 2007 two track demo billed 'Lava Poetry' comprised 'The Unreal Locations Of The Period Of Stones' and 'Petrified Hermits'.

In early 2007 PHLEGETHON members vocalist Jussi Nyblom and drummer Lasse Pyykkö formulated high speed Death / Grindcore Metal band COFFINS OF CYST.