Terhen was formed in January 2004 under the name Thamuz. Back then they had a few disagreements in choosing the music style and there were also some problems with the members. The band made four songs and in May 2004 recorded them for rehearsal purposes only. The demo represented their interests in strong black/death metal influences.

After getting some new material done Thamuz got an opportunity they couldn't resist: they were offered to make a music clip for a fashion show in Beijing. The show succeeded well and the band was satisfied with using this unusual way of promotion.

They went into a studio in October 2005. A demo called Self Crusifixion MMV contained three songs which are also included in the debut album. Soon after the recording session the drummer left because of lack of time, but luckily he will remain in the crew as a lyrics writer. In general the demo achieved good feedback among reviewers and friends.

The band sent a demo to various record companies and to the media. Soon after this they signed a deal with Firebox records and changed their name to Terhen.

On making the album, Terhen decided to continue co-operation with Mikko Suuronen, who also recorded the Selfcrusifixion MMV demo. They also hired a separate producer, Risto Ylönen, to the recording session. It was a great use to have more people working, because there were more opinions about the music.

The process started in February by recording the drums with the new drummer Joni Romo. The album was mainly recorded on weekends and after every recording sessions the material started to sound more and more like real music. Besides the new drummer the band has got a second vocalist Elisa Pellinen, whose voice is a great add to the music. The debut album Eyes Unfolded was release in August 2007.