Ditch the doublet: A fresher form of historical fiction is reclaiming lost stories

As you can't fail to have noticed, this year is the 500th anniversary of Henry VIII's accession to the throne. You will, no doubt, be equally familiar with his less than uxorious tendency to chop off the head of any wife who gave him trouble. Henry's insatiable sex drive, his daughter Elizabeth's much-vaunted virgin status: from novels to movies and TV costume drama, the Tudors have long been a historical soap opera for the British.

Yet when the history itself was actually happening, England was not such a big deal in European power politics. Indeed, every time a new novel about another of Henry's squeezes drops on to my desk, I find myself thinking of that sketch in Monty Python: "No parrots killed in multiple pile-up on M1". While we are not alone in practising historical chauvinism, given the riches of Renaissance Europe it seems rather parochial to spend so much time in the bedchambers of Hampton Court.

Perhaps I should declare my hand. I grew up largely suckled on the teat of Tudor historical fiction; I wrote a short novel about Elizabeth I when I was 14 – short, that is, except for the adjectives, of which there were at least three for every noun. Obsession, in the hands of a good history teacher, turned into more inquisitive thinking and three years under the academic whip at Cambridge beat the romance – and the Tudors – out of me (the pain, I hasten to add, was almost all pleasurable). While I knew I wanted to write, fictionalising real history with its rock strata of complexities seemed just too difficult.

Then, ten years ago, I spent a summer in Florence. I was nursing bruises sustained from bumping my elbows against the hard-edged rules of writing thrillers and looking for a new way forward. Underneath the encrustations of souvenir shops and tourist litter, Florence still pulsates with a history that – though it has its fair share of scandal (Lorenzo de Medici once wrote a carnival song in praise of the joys of sodomy in marriage) – was monumental in so many other ways.

While the Renaissance was taking place, a large proportion of Englishmen were still out tending sheep. And its blending of new ideas, be they political, religious, philosophical or artistic, must have made for the shock of the new for those living through it. So could one write a novel in which that sense of revelation – the excitement and queasiness of the world turned upside down – came through? The question turned me into a historian again.

Back inside the libraries, I had another revelation. The past itself had changed. In the 30 or so years since I last handed in an essay, history had undergone its own revolution: the rule of kings, queens and great battles challenged by the slow march of "ground-up" history, the impact of Marxism, feminism, and a host of other "isms", committed to seeing the past through the eyes of those on the margins.

I had been aware of this warfare within the larger cultural conversation, but it was only when I started thinking about fiction that I became intoxicated by the possibilities. To begin with, the revelations were just so damned colourful. For the historians it was obviously hard work – deep-vein mining in state, church, city, even parish records and archives. But for me, it was gold dust. The more I read, the more the Italian Renaissance came to life in my hands, be it the prosecution of homosexuality in Florence (a crime thundered against in the pulpits and all too obvious in the streets), the secret lives of courtesans, the black African slaves, the hidden world of nuns.

Reading this history was liking watching a pointillist painter at work: a thousand dots of fact, so that when you finally stood back and looked at the whole teeming canvas, the picture had new depth. The discovery of perspective in history is now as powerful as it once was in the world of art.

With this kind of unearthed treasure, why bother with another novel about the lives of the already famous? Not only do we know their stories (narrative tension is much harder work when the end is not a surprise) but, like contemporary celebrities living in a continual spotlight, their rarefied position meant that there were elements of life as it was really lived that they simply had no clue about.

Which brings us to women. With a few notable exceptions (snake-eyed Ann Boleyn and her fabulous red-headed daughter, Elizabeth, being two of most memorable), history had been shamefully empty when it came to recreating the lives of half the human race. And it was particularly bad in its study of the Renaissance. Such was the deafening silence of women that, 30 years ago, a young historian called Joan Kelly was moved to write a paper called "Did women have a Renaissance?" It's one of the questions I have been grappling with since I embarked on that Florentine novel that became The Birth of Venus. The answer has taken me into merchant houses and palazzos, brothels and high-class courtesans' houses – and most recently into what from our perspective can only be described as elite prisons: Renaissance convents.

The statistics will make your eyes water. By the end of the 16th century, something like half of all reasonably well-born Italian women were in convents. Come the onset of menstruation, such was the threat their sexuality presented to society that young women either had to be married off pronto or, if their fathers couldn't afford it (and dowry inflation was rampant), be wedded to God. As Isabella d'Este, one of the few women to raise her head above the parapet of Italian Renaissance history, put it so charmingly in a letter: "Christ is the one son-in-law who doesn't cause me any trouble".

So what exactly went on behind those formidably high walls? Thanks to an army of scholars, we know a great deal more than we used to, and all of it is riveting in terms of both horror and wonder. Needless to say, not all women went willingly. Unsurprisingly, the daughters most likely to attract husbands were the good-looking, healthy ones. Birth defects, a cruel attack of smallpox, an excess of spirited individuality, too much intelligence or too little... all this might have counted against you. Not to mention any potential for mental instability.

"Our Novice Mistress, overpowered by those moods and frenzies of hers, tried twice in recent days to kill herself," writes Sister Maria Celeste to her father, Galileo, in 1629, explaining a hiatus in their correspondence. "First she struck her head and face against the ground so forcibly that she became monstrously deformed... then she stabbed herself 13 times".

Those letters, translated by Dava Sobel in 2001, are just one of many tantalising glimpses history now offers into convent life. Imagine, for example, the cunning of the two young nuns who dug a hole in the back of the storeroom and over a period of years entertained their lovers there. Or the wildness of the abbess who had two children by the landowner next door and, when a serving nun discovered her secret, battered her to death with a shovel and had her body thrown down the well. Or the convent on one of the smaller islands in Venice, where the father confessor regularly delivered more than just confession to his flock. Or the nun hailed as an ecstatic visionary with stigmata, until someone spotted her sticking needles into the wounds in her hands.

On the other hand, it was not all hardship and transgression. Compared to life outside (arranged marriages and repeated pregnancies, with a high proportion ending in the death of either the mother or the child), convents offered women respite, peace and even space for creativity. Those same scholars who unearthed scandals and horrors also found success stories – women exploring profound states of spirituality, copying and illustrating manuscripts, composing plays, arranging and even writing music.

From such fertile soil, rich fiction can grow. Sacred Hearts, set in a Benedictine convent in Ferrara on the cusp of the Counter-Reformation, began with the sound of a girl newly incarcerated, screaming into the night. It ended three years later as a novel about faith, hysteria, politics and power, a story of a republic of women under the guidance of a smart, capable abbess of good family, intent on balancing pragmatism against piety, conformity against creativity. For those who still see historical fiction as an excuse for the ripping off of bodices and codpieces, it will I hope, be a revelation. And you can take that word any way you want to read it.

Sarah Dunant's 'Sacred Hearts' is published by Virago; she will be speaking at the London Literature Festival, at the Royal Festival Hall on 2 July: www.southbankcentre.co.uk

Period pains: writing historical fiction

Rather than attempting to discover new material from national archives and libraries, which historians will have gone to time and again, conduct some deep-vein mining in more surprising, less excavated areas - such as parish records and small university archives.

Concentrate on breathing life into the 'hidden histories' of ordinary people rather than figureheads whose life stories have already come to light. Opt for telling the tale of a formerly anonymous Victorian courtesan, servant or nun, rather than that of Queen Victoria herself.

Bring a sense of many perspectives to one historical event, so that a story of a particular period is told through various voices rather than just one viewpoint. This process can be likened to the thousands of dots used in a Pointillist painting to build a full picture.

Women's histories are an untapped gold mine, with the history of Elizabeth I and Mary Stuart perhaps being two rare exceptions. History is shamefully empty of fine female historical figures so creating a roll call of eminent women in history will lead to the telling of new biographies.

Concentrate on unearthing a scandal over the more parochial story, ideally with an edge of the gruesome or Gothic. Themes of madness, incarceration and spirituality have proved successful.