Gamma Ray was the project of ex-Helloween guitarist Kai Hansen and ex-Tyran Pace frontman Ralf Scheepers. Adding the rhythm section of Uwe Wessel (bass/vocals) and Mathias Burchardt (drums). Armed with songs left over from his Helloween period Hansen entered the studio to complete their debut set Heading For Tomorrow on Noise' in 1990. The album met with acclaim and comparisons to Hansen's old outfit. The platter also featured the first published line-up, and several changes had been made during this period settling on Ralf Scheepers, Kai Hansen,Uwe Wessel with new replacement members Dirk Schlachter (guitar/keyboards) and Uli Kusch (drums).
After taking the act on tour their sound was improved for the second set Sigh No More (1991) with Insanity And Genius following some nine months later in 1993, but it proved to be obsolete before it was released due to their Euro-Metal sounds now becoming dated. Nonetheless they continued on with their styles to release the follow-up Land Of The Free (1995) with new members John Rubach replacing Wessel and Thomas T. Nack replacing Kusch while Scheepers departed for Primal Fear and Hansen took over vocals. The album struggled in a world now saturated with Heavy Metal; their subsequent European tour was recorded on Alive 1995 (1996).
1997's Somewhere Out In Space ushered in a stable line-up including Hansen and Schlachter with Henjo Richter (guitar/keyboards) and Dan Zimmerman (drums). The follow-up, Power Plant (1999), came and went, no longer internationally released as in the past, as was the millennium issue No World Order (2000), proving that at least in some parts of Europe the demand for their style of Germanic Hard Rock hadn't disappeared entirely. The big surprise was their 2001 release of Blast From The Past, their best of retrospective compilation whose tracks were picked from an Internet vote and re-recorded by the original line-up. The current line-up was back in action for the live set Skeletons In The Closet (2003) and the Land Of The Free II (2007) proving to be a very successful successor to the earlier sequel.
To the Metal! (2010) arrived to modest critical praise, but disappointed some fans that expressed concern that it was uninspired and a weaker effort than the previous album.
In May, 2011, Gamma Ray released the EP Skeletons and Majesties. It contained newly recorded, rarely played material (Skeletons) and acoustic versions of other older songs (Majesties).
On September 1, 2012, the band announced Michael Ehré as their new drummer, replacing Daniel Zimmermann.
Empire of the Undead was released with a more thrashy sound in March 2014, despite the band's studio being completely destroyed by a fire.