England's Mistress by Kate Williams

The current determination of publishers to stress the contemporary relevance of historical figures can be off-putting - does Emma Hamilton really have to be described as "Britain's First Media Star" to attract our attention? Do we need comparisons with the Beckhams to understand how glitzy a couple she and Lord Nelson were, or how obsessed the papers of the day were with them?

Part of the attraction a prominent figure from a different era holds for us, especially one as popular as Emma Hamilton, is precisely her difference. Kate Williams has done a wonderful job recreating the life of the woman she wants us to relate to - yes, she says, Emma worked as a prostitute in London in the late 18th century, but so did "one in eight of all London's adult females". And Emma's favoured loose style of dress made her a "style leader", with women all over Europe copying her "look", as Williams's extensive reference to magazines of the day makes clear. A sort of Kate Moss/Posh Becks combo with a touch of Christine Keeler thrown in, then.

Yet these contemporary parallels are unnecessary. This is an immensely colourful, readable portrait that revels in Emma's resilience and her ability to surmount what look to us now to be unimaginable odds. Williams resists psychological speculation on Emma's motives in order to concentrate on the facts of her life and its context without relinquishing a sense of who Emma was; not an easy trick to pull off (she does make one slip - it wasn't Mary Shelley who "died in agony after a doctor tore out her undelivered placenta with his bare hands", but her mother, Mary Wollstonecraft).

Born Amy Lyon in 1765 to an impoverished couple in Cheshire, the future friend of the Queen of Naples headed off to London alone when she was 12 for employment as a domestic servant. At 13, she was applying at Drury Lane to be an actress, and within a year, working as a prostitute. She also posed as an artist's model and worked in the dubious "Temple of Health", a sort of sex-help exhibition, before joining the notorious Mrs Kelly's brothel just off Picadilly. She was found there by Sir Harry Fetherstonehaugh who took her off to his country estate, before abandoning her when she got pregnant with his child.

His less flamboyant friend, Charles Greville, the younger son of Lord Brooke and the nephew of Sir William Hamilton, the English ambassador to Naples, was obsessed with her and he rescued her - after a fashion. With him, she had to cultivate the appearance of the "penitent prostitute" and follow all his rules, but once she began sitting for the artist George Romney, and his strikingly beautiful paintings of her attracted public curiosity, Greville grew jealous and attempted to pass Emma on to his uncle in Naples.

Williams argues that Emma was horrified by this ploy, but that she soon grew to love William Hamilton. She would pose as figures from antiquity in her series of "Attitudes" (once witnessed by Goethe) which soon became the talk of Naples, and eventually, after realising that he couldn't do without her, Hamilton made an honest woman of her. The Queen of Naples became a special friend, and at the height of the Terror, Emma openly supported Marie Antoinette and would later help the Queen escape the advancing French troops. It was war that undid their marriage, for Williams, over 60 and indulgent, had little chance of keeping her once the great hero Nelson arrived.

The relationship between Emma and Lord Nelson is characterised by intensity and massive spending. Back in London they became the talk of the town, throwing lavish parties for their famous friends and overspending on the decoration of their flashy new home. It was all to end in tragedy of course - once Nelson died, Emma carried on spending but without the money to fund her tastes. Creditors and the inconstancy of fair-weather friends soon forced her to flee, and she died in poverty abroad while still only in her forties.

Williams is keen to stress the multifaceted nature of Emma Hamilton in an attempt to portray her as a woman of modernity: "Model, courtesan, dancer, fashion icon, actress, double agent, political hostess, mother, ambassadress and hero's mistress, Emma Hamilton performed many roles in her astonishing rise from poverty to wealth and fame."

But Emma was very much a woman of her time - not a political revolutionary, maybe, but a revolutionary in the way she broke down class barriers, undermining public attitudes about what a poor, uneducated woman could become. This was the era of Mary Wollstonecraft and women's rights; it was also the era of the courtesan, of the infamous Harriette Wilson. Before the strictures of the Victorian era closed off many women's choices, it was possible that a woman born in poverty could rise to riches and respectability. That, surely, is the importance of Emma Hamilton to us today. Not just how she manipulated the media, or how many pairs of shoes she possessed.