Formed in the late 60-s by Daevid Allen (ex-Soft Machine, Mother Gong-Daevid Allen) with Robert Wyatt (ex-Soft Machine), Gary Wright (ex-Spooky Tooth), Maggie Bell (Stone The Crows), Didier Malherbe (Hadouk Trio), Cristian Trish and Pip Pyle. They made numerous albums in the early 70's with this original lineup.
A number of Gong-related bands have existed over the years, including Mother Gong, Gongzilla, Pierre Moerlin's Gong, Planet Gong and Gongmaison, Gong Expresso.and there are even more. Search for the artist name of Gong on Proggnosis and see the listing.
Additional information about all things Gong can be found on the expert website located at not just another GONG website.