It's an erotic classic yet it was written anonymously by a shy, intellectual French woman in honour of her secret lover. Fifty years on, Geraldine Bedell goes in search of Dominique Aury, one of the first women to write frankly about sex.

Fifty years ago, an extraordinary pornographic novel appeared in Paris. Published simultaneously in French and English, Story of O portrayed explicit scenes of bondage and violent penetration in spare, elegant prose, the purity of the writing making the novel seem reticent even as it dealt with demonic desire, with whips, masks and chains.

Pauline Reage, the author, was a pseudonym, and many people thought that the book could only have been written by a man. The writer's true identity was not revealed until 10 years ago, when, in an interview with John de St Jorre, a British journalist and some-time foreign correspondent of The Observer, an impeccably dressed 86-year-old intellectual called Dominique Aury acknowledged that the fantasies of castles, masks and debauchery were hers. Click here for the full article