The real princess. Marie-Antoinette has been the subject of countless biographies, but none brings her to life more fully than Chantal Thomas's vivid historical novel. By Hilary Mantel

Farewell, My Queen

Chantal Thomas, Translated by Moishe Black <em>Weidenfeld & Nicolson, 256pp,

Dead princesses are a thought- provoking topic, especially when the story that should end "she lived happily every after" has a premature and bloody finale. One of the shrewdest judgements on the late Diana, Princess of Wales was made by Sue Townsend, who des-cribed her as "a fatal non-reader". You can see the force of this; brought up on Barbara Cartland, she had not come to grips with how the plot of her life would twist and turn, from rosy dawn into an enveloping hostile darkness. What Chantal Thomas has discovered in Marie-Antoinette is a similar failure to read her life. She had a butterfly's attention span, and it was said that she never finished a book. Perhaps, Chantal Thomas has wondered, it was because she didn't want to know the end? The most feted princess in Europe was doomed to wretched imprisonment and death during the Terror of 1793; in her days of glory, she did not know which story she was in, or who its author might be.

Thomas is a specialist in 18th-century history and literature; her 1989 book La Reine scelerate (translated as The Wicked Queen, Zone Books, New York) is a fascinating account of the myth of Marie-Antoinette as it had evolved by the time of the revolution. The myth formed itself out of scraps of folk tale and fairy tale, out of dream-images of devouring mothers and rapacious wives, out of legends of succubi and man-eating demons which could take on, during daylight hours, the alluring form of a princess. Daylight saw diamonds and silk; nightfall brought the claws and the teeth.

Meanwhile, pamphlets and political satires - many of them written by cour-tiers, rather than radicals - produced what Thomas called a "caricatured double" of the queen: a libidinous, perverse, even incestuous figure, a "political tarantula" who took time out from self-indulgence only to hatch treason and bend her lumpen husband to her will. These images bore no relation to the real-life queen, but it was hard for her to counter them - she had the personal misfortune of being Austrian, and the more culpable misfortune of being ignorant and scornful of public opinion. Stories about her were independent of facts. Princesses walk their own airy path in a realm of archetype. The adoration of a 20th-century princess and the vilification of an 18th-century queen are two sides of the same ancient coin. As Thomas puts it, "Myth has a life of its own, based on an internal logic . . . It is independent of its support; the latter may die the physical death of the body, but the myth still hovers over the cadaver."

Marie-Antoinette is the subject of hundreds of biographies and novels, but perhaps none of them brings the reader quite so close to her as Farewell, My Queen. And there are very few historical novels that create, as this one does, a shiver of uncertainty in the reader. If you can marry stringent research with creative freedom, your novel will breathe, you hope, an uncanny verisimilitude. However refined, oblique or postmodern your approach, you do hope to work, at some stage, the oldest trick in the book: to upset your readers into the irrational belief that you were a witness to the version of the past that you are selling them. You hope to create the illusion of multiple realities, one of which includes you: to collapse the time-frame.

Thomas's narrator, the genteel young Agathe-Sidonie Laborde, reminds us that time at the court of Versailles was different from ordinary time. It was purely ceremonial; it was spent differently, marked off by curious signposts. The unit from which the divisions were calculated was not the year, or the month, or even the week, but the day. There was a Perfect Day, whose programme had been set more than a century earlier . . . Every day since that time was supposed to re-enact the Perfect Day.

The day which shatters the perfection is the day of the fall of the Bastille. Paris is another country almost, but now its customs and people cannot be ignored. Through the eyes of Agathe-Sidonie, the queen's lectrice - she reads aloud to her, and tries to fix her wavering attention - we follow events between 6am on 14 July and midnight of 16 July 1789. The author's imaginative fluency and her close acquaintance with every detail are astonishing; her writing is delicate, aerial, precise.

Yet what she describes is a rout; the irruption of one myth into another, the myth of the people's power bursting violently through the scrupulously maintained unrealities of the old regime. She offers us the scent of lilac essence and burning papers, the sight of the hapless king dining on fatted pullet and skate liver, minced wildfowl and "an ocean of green peas". She leads us through the "exudation of the commodes" and the blinding smoke from the palaces' great fireplaces, and into the private salons filled with whispered rumour, where - for the first time in living memory - yesterday's flowers are wilting in their vases; she allows us a glimpse into the queen's eye of leaden blue, and of a face that takes on an expression of the "non-human" - as devoid as a marble statue of any idea of the nature of the forces that will topple it.

She describes flight, the flight of cour-tiers: the abandonment of dinners uneaten, of birds in their cages, of the tiny black slaves who carry parasols, of pet dogs and even children, as the courtiers precipitate themselves into the void. "I tried . . . to picture the world outside Versailles. No picture formed in my mind." In exile and old age, Agathe-Sidonie writes the novel as a postscript to her life, a final flourish, in which only a beat of the pulse separates the lectrice from her enthralled reader.

Hilary Mantel's most recent book is Giving Up the Ghost (Fourth Estate)