The German Trance DJ's and Producers Claus Terhoeven (Nic Chagall) and Stefan Bossems (Bossi), met in 1997 while they had several releases with different projects for X-IT Records in Cologne. In November 1998 the duo met by chance in a studio, and decided to do a track together. The end result was a track called The Drums and the duo's first exploration in to Hard Trance; Cosmic Gate was born.
At this point the duo was forced to quit their resident DJ jobs to have enough time for remixes, DJ gigs and new productions.
In 2006 they released their third studio album, Earth Mover which was very different from previous Cosmic Gate albums as it no longer had the distinctive Hard Trance sound that they were known for. Their sound evolved even further on the fourth album, Sign Of The Times (2009) which took a more 'progressive' approach to Trance music, which also reflects the duo's DJ sets.
Recently, Stefan is only behind the decks as a part of the duo, so the Cosmic Gate tracks are made by Claus and the co-production of Olaf Dieckmann (Wippenberg), since the latter stopped doing his solo career.
In 2018, Olaf and the duo were nominated for Grammy Award for the Cosmic Gate remix of The Only Road by Gabriel & Dresden featuring Sub Teal. It was the 61th Grammy Awards, category 71 Best Remixed Recording.