TNT was founded in Trondheim, Norway in 1982 by ex The Kids singer Dag Ingebrigtsen (vocals), Ronni le Tekrø (guitars), Steinar Eikum (bass) and Diesel Dahl (drums).
Their debut album (TNT - 1983) was somewhat special since the lyrics were Norwegian. It is still rated as a classic album in Norwegian music history.
Steinar Eikum left the band after their debut album and was replaced by Morty Black. Dag Ingebrigtsen originally wrote the lyrics for their next album in Norwegian. Before recording the album he left the band and was replaced by American singer Tony Harnell. Harnell made new lyrics in English, and their next album, Knights of The New Thunder was a kind of breakthrough for the band. They got a hit with the musicvideo made for Seven Seas. Tell No Tales (1987) was the big breakthrough for the band. They made success, especially in USA, where they hit the Billboard Top 100 charts. They toured USA and Japan. Internal problems in the band resulted in Diesel Dahls departure. He formed his own band, TinDrum.
Ken Odiin replaced Diesel as drummer and in 1989 the band released Intuition. Some disagreements on the progress in the band resulted in a pause. Ronni le Tekrø and Morty Black formed a hobby band called Bad Habbitz, who played cover songs og Thin Lizzy as well as the band Vagabond. In 1992 a new album called Realized Fantasies was released. Ken Odiin quited the band after the release of Intuition. The new drummer was John Macaluso from New York. He quited the band after disagreements during the Japan tour and formed the band ARK with Tore Østby. Another pause followed before they released the album Firefly in 1996. New drummer was Frode Hansen from the band Jack in A Box. After some concerts in Norway and Japan, Tony Harnell left the band to form his own band called Westworld. A year later Harnell rejoined the band and they released Transistor in 1997. Despite a new album the band did not tour and Harnell left the band again to keep Westworld alive. In 2003 the band released a greatest hits album called The Big Bang. Following the release the band started working on new songs. Diesel Dahl returned to the band and they released an EP called Taste. The following year, in 2004, they made the album My Religion.
Morty Black left the band in 2005 and was replaced by Sid Ringsby for a short period. Ringsby played bass on their next album, All The Way To The Sun, and was replaced by Victor Borge shortly after.
Tony Harnell left the band again in 2006 and the live album Live In Madrid is his second last performance with TNT.
The search for a new singer gave results. English singer Tony Mills (ex Shy) joined the band. After a creative period in Ronni's studio the band made lots of new material which resulted in the new album called The New Territory.