This Dutch group was one of the earliest Continental European progressive rock bands.

The history of GROUP 1850 (aka GROEP 1850) starts from year 1964 from the band called THE KLITS. There were several changes in the line-up's during the the decade their career lasted, only Peter Sjardin remained as the permanent member of the band. Their first public performance with the name GROUP 1850 was in the Scheveiningen Casion in March 1966. Their gigs gave them attention in the underground scene, and some single releases and radio airplay in Holland followed. In September 1967 they warmed up MOTHERS OF INVENTION at the Amsterdam Concertgebouw, and their first longplayer "Agemo's Trip to Mother Earth" (1968) has been stated as the first Dutch concept LP.

Acid rock elements are clearly present in their first albums from the end of 1960's, and PINK FLOYD's "Saucerful of Secrets" album has surely been an innovator for them, like to so many other spaced out groups. Their music isn't an exact copy of their innovator's sound though, as there is a wide spectrum of different styles merged to the band's music in custom of psychedelia's artistic freedom. The overall feeling of the band's early music is nonrelaxed but not very aggressive, probably pleasing the fans of music describings a cosmic journey within one's mind.

The career of the band continued with both inactive and active periods and with continuous changes in the personnel. Musically maybe the most important event was release of the album "Polyandri" in year 1974. Their mostly instrumental music grew to a larger scope containing strong musical elements.

In the same year the keymembers of the GROUP 1850 performed with the name ORANGE UPSTAIRS (Oranje Boven). The released one album with this name and then changed back to GROUP 1850. The band broke up in 1975, and the members went to join other bands. The original vinyls of the group's releases have reached high prices in the collector's markets.