Circle were formed in 1992 by bassist and singer Jussi Lehtisalo, the only member who has been in the band throughout its career. Circle's krautrock-style debut album Meronia was released in 1994 and featured lyrics in a made-up language. A trio of albums, Andexelt, Prospekt, and Taantumus, brought them international attention.
Circle members have participated in a great number of side projects and split-offs, including stoner rock spin-off Pharaoh Overlord. Rättö and Lehtisalo play as a duo, Rättö ja Lehtisalo, and as a trio with Kauko Röyhkä. Other projects featuring members of Circle include Steel Mammoth, Ektroverde, Janne Westerlund's Plain Ride, Lusiferiinin Armosta, K-X-P, Aavikko, Lehtisalofamily, Split Cranium Moon Fog Prophet, and Doktor Kettu.