What French actor played Gigi on the London stage before starring in film version?

There was no French actor to play Gigi on the London stage before starring in the film version. Gigi is a French novel written by Colette and first published in 1944. The novel tells the story of a young girl growing up in Paris in the 1900s. The film adaptation of the novel was released in 1958 and starred Leslie Caron as Gigi, alongside Louis Jourdan, Hermione Gingold, and Maurice Chevalier. Leslie Caron is a French actress and dancer, but she did not play Gigi on the London stage. The role was played by Cecil Beaton, who was a British fashion designer, stage and film designer, and artist.