Therion is a metal band founded by Christofer Johnsson in Sweden in 1987. Therion was initially a death metal band. However, starting with 1995’s Lepaca Kliffoth, Therion began to gradually incorporate symphonic elements into their metal music. Already on 1998’s Vovin they employed heavy use of choirs and classical musicians, not only as additions to but also as integral parts of the composition.

Therion takes its lyrical themes from various mythologies, occult and magical teachings, and ancient traditions and writings. The majority of the lyrics are written by Thomas Karlsson, head and founder of the magical order Dragon Rouge, of which Johnsson is a member. The band’s name originates from the Greek word therion (θηρίον), which means beast, in reference to the “beast” of the Christian Book of Revelation, though the word itself is taken from the Celtic Frost album To Mega Therion.

The band has seen many changes in line-up and style throughout its history. Only Christofer Johnsson, Kristian Niemann (guitar), Johan Niemann (bass), and Petter Karlsson (drums) are considered the constant members. All others, including vocalists like Sarah Jezebel Deva, Piotr Wawrzenuk and Mats Levén, are sessional members. Therion maintain a web site at http://www.megatherion.com/.

There was also a thrash metal band from UK called Therion. They released one demo during the 80’s.