Debussy once asked Mallarme if he could set one of his poems to music. But, replied Mallarme, have I not already set it to music? Hilary Mantel has decided to treat the French Revolution as a novel. But was it not already a novel? The Revolution forms a concentration of extraordinary events that defies ordinary belief. Such a tumultuous and incoherent story of violence, accident and fear is already the stuff of fiction.

But Mantel is right. No historian can explain, except to the reluctant satisfaction of other historians, how it was that within a very short period of time France was beset by civil war and rejected the principles by which its society had been governed, namely, the monarchy, the Church and the aristocracy. And then, within a few years, France emerged as a solid, surviving state, dominated by a conservative peasantry and a self-satisfied bourgeoisie. To understand this we have to use our imagination. Mantel, having read many history books, takes us into the private world of the leading revolutionary characters. In a novel of more than 800 pages, a series of short scenes brings us into intimate contact with those who are the official leaders of the revolutionary process. The dominant figures are Camille Desmoulins, Georges Jacques Danton and Maximilien de Robespierre. They all have difficult childhoods; they are imbued with a sense of destiny; they meet in Paris; they associate with many women who play an important role in the narrative. And they are surrounded by a gigantic cast: Mirabeau, Fabre d’Eglantine, Lafayette, Saint Just, the King, the Queen, Henri Sanson (the public executioner) and scores of others.

No one evades the memory of this well-informed novelist, although she apologises for not making Marat a more central character and she promises to write a book particularly about him. Yet it is Marat, with his gold flecked eyes and a filthy handkerchief tied around his neck, so repellent that no gaming house would admit him so that he had never tried his infallible system for winning, so devoted to the Revolution that he thought about it twenty-four hours a day, who utters the phrase that is the key to this work. ‘It’s like a storybook, isn’t it?’ he says.

Of course there are dangers in this method. We must all have recollections of a film in which two knowing Frenchmen whisper to each other in Hollywood accents. ‘If I were you,’ says the one, ‘I’d keep my eye on that little fellow over there. He’s a bit special, I guess.’ ‘Oh,’ says his friend, ‘what’s his name?’ ‘Just a minute,’ comes the reply, ‘Oh yes, it’s something like Bonaparte. That’s it! Napoleon Bonaparte.’

The Duke of Orleans saying that Saint Just is not a very friendly young man; Desmoulins claiming that he could get Robespierre over his horror of death sentences; General Doumouriez remarking that if Marat took any baths at all, whatever their nature, this could only be an improvement; the young Danton, newly arrived in Paris, contemplating the Bastille and being convinced that it was impregnable. Such episodes can be compared to the easy irony of B-movie history-speak.

But the book is not like that. It is made up of a well-planned and skilfully contrived series of conversations, interspersed with genuine quotations and a neat commentary on events. We are shown the officials drawing up the lists of those who are to be executed. As the pen skips over a name, how can one associate it with the corpse that it might be tomorrow? But in the room where this is happening there is no sense of guilt. Only a dismal camaraderie.

Who is to do the killing? At first it was thought that butchers could be enrolled in return for special payment. But enthusiastic and unskilful beginners joined in and botched the job. In any case, the lists turned out to be useless; those who were killed were not those who had been designated. The people were translated from having been heroes, to being scavengers, savages, cannibals.

‘When will it all end?’ asks one character. But when his daughter, Lucile, opens the door, she is given ‘a sucking greedy, proletarian kiss’ by a large man who smells of wine, tobacco and blood. He gives her a heavy, silver-backed hairbrush taken from the Queen’s dressing table and inscribed with the initial ‘A’. ‘What a legion of admirers you have,’ says her companion sarcastically. ‘Well,’ replies Lucile, ‘I just say to them, “Now boys, stop quarrelling over me. Liberty, equality, fraternity – remember?”’

All the main characters watch each other. This is a revolution of wariness and circumscribed heroics.

Desmoulins looks sadly back on his past and remembers how, when he was six years old, he could read Greek as easily as his sister could read her fairy stories. But his father was not impressed. He went on wondering why it was that he had been given a son who stammered. Danton boasts that he has worked hard to make the national interest coincide with his own. And Robespierre? He smiles his thin smile and reflects that if he were remembered in the next generation people would speak of his thin smile. He always wanted it to be different.

Clearly it is Robespierre who fascinates Hilary Mantel (but can we really believe that his contemporaries called him Max?). As Danton puzzles over him, it is the author who is puzzling and wondering if there was some layer, some deep stratum, where all his many contradictions were resolved. It is curious then that she ends her book with the executions of Desmoulins and Danton and not with that of Robespierre which took place shortly afterwards. The story is told that as he lay wounded and bleeding profusely, a man helped him to be more comfortable. Robespierre said, ‘Thank you, Monsieur.’ He spoke the language of the past; he did not say ‘Citizen’. Did he know that the Revolution was dying with him? Or is it just another contradiction?