A trip to Florence with her shopping-obsessed daughters inspired Sarah Dunant write to historical novels investigating the secret lives of Italian women. By Barry Didcock

As you would expect, Sarah Dunant's comfortable north London home is free of dwarves, courtesans, charismatic artists and scheming nuns. They do all feature in her fiction, though, and readers of The Birth Of Venus and In The Company Of The Courtesan will recognise most of them well enough.

The nun is new to the company, however. Her name is Madonna Chiara and she's central to Sacred Hearts, the third in Dunant's triptych of historical novels set during the Italian Renaissance.

Chiara is abbess of the convent of Santa Caterina in the northern Italian city of Ferrara. The place is also home to the scholarly Suora Zuana, who runs the dispensary, and 16-year-old Serafina, a novice who claims her vows came from her mouth not her heart. She's young and in love and while Christ has his appeal, she would prefer a husband with moving parts. The year, by the way, is 1570.

Right now it's just the author and me and the two mugs of tea we've carried upstairs from her kitchen. I did pass a woman painting in the hall, but from the overalls and the tin of emulsion I'm guessing it was an undercoat rather than a fresco that was being worked on. Later, Dunant's younger daughter Georgia will enter the room, though she too is on a very 21st century errand. She wants to check her emails.

As well as the Renaissance itself, Dunant's loose trilogy has another subject: the secret lives of women in an era dominated by men. Women such as Alessandra Cecchi, 14-year-old heroine of the first novel; like Fiammetta Bianchini, the titular courtesan of the second; like Serafina, Zuana and Madonna Chiara.

"That's the grand project," says Dunant. "It began when I took my two daughters to Florence ten years ago. I said: I know a lot about the Renaissance, you're going to love this.' One of them turned to me and said: I don't do culture, I do shopping.' I thought: What am I going to tell them that will appeal to them when everything I'm reading is about men? What happened to the other half of the population during this seismic revolution?' So that's been the arc of these three books."

The Birth Of Venus is set in Florence in the late 1400s and turns on the relationship between Alessandra and a painter commissioned to paint the walls of the family chapel. In The Company Of The Courtesan moves on three decades and is set in Venice, though it begins with the sacking of Rome in 1527 by German Lutheran soldiers opposed to Clement VII. The narrator is the dwarf Buccino, Fiammetta's friend, advisor and pimp.

Sacred Hearts is a tale of political intrigue set within the imposing walls of a place few men ever saw. Religious duties dominate the nuns' lives - Lauds, Vespers, Compline and Matins are just a few of the other daily orders and offices a 16th century Benedictine convent would have observed - but there is also time for food, fashion, gossip and music.

"Women could be quite creative there," says Dunant. "They were singing a great deal, and some of them, we now know, were composing a great deal too. They were also taking compositions by people like Palestina and re-working them so that women could sing them."

But this is also a story told against a background of great change in the outside world. As dowry inflation crept up and up over the course of the 16th century, around half of well-to-do Italian women could expect to end up in a convent by the time the novel is set. Many would go against their will.

At the same time, the ongoing struggle between those supporting the Reformation and those opposing it meant the running of religious houses was coming under increasing scrutiny.

"The Catholic church was so frightened of Luther's propaganda about how chastity didn't work that it came down very hard on the nunneries," says Dunant. "It took them out of control of the noble families who ran them. It put up walls, literally. It bricked up windows. Before that, there was actually a fair amount of freedom within convents, if you compare it with what life was like generally as a woman in 16th-century Italy."

That Dunant knows her history is evident before I even meet her. Prior to her career helming arts programmes on television, she studied the subject at Cambridge University's women-only Newnham College.

Meanwhile the extent of the research she undertook for Sacred Hearts is revealed in an impressive bibliography in which the university presses of Oxford, Cambridge and Harvard dominate. It isn't what you'd call a light reading list.

It does, however, illustrate a trend in modern historical writing - that the subjects