From the Jean-Claude Forest Home Page:
Jean-Claude Forest created the character of Barbarella for V-Magazine in 1962, at the request of its editor, Georges H. Gallet, who was already familiar with Forest's work as France's premier science fiction cover artist and had commissioned an illustrated version of Catherine L. Moore's classic story Shambleau in 1955.
Barbarella was published in book for by Eric Losfeld's publishing company Le Terrain Vague in 1964, became an immediate runaway bestseller and was soon translated in a dozen countries, including by Grove Press in the United States. Not long after, it was adapted into a 1968 motion picture, produced by Dino de Laurentiis, directed by Roger Vadim, and starring Jane Fonda, for which Forest acted as design consultant.
A Forest Barbarella design from the abandoned Nelvana animation project: