With his new novel, one of the major events of an autumn rich in fiction, the Booker-Prize winning novelist enters modern times Photographs by Andrew Buurman
Barry Unsworth is, by any standards, one of our senior novelists. He won the Booker Prize for his powerful and stirring description of the slave trade in Sacred Hunger, and has been on the shortlist on two other occasions (for Pascali's Island in 1980 and for Morality Play last year). His work has been filmed (Ben Kingslay starred in Pascali's Island) and a six-part dramatisation of Sacred Hunger (with a screenplay by Unsworth himself) is being produced by Channel 4. In a 30-year literary career, he has written a dozen novels.

If he is not exactly a household name, that is probably because his books, for the most part historical novels with foreign settings (and a modernist's touch), cannot easily be given fashionable, high-concept tag-lines by his publishers. They do not "deal" with drug addiction or child abuse, and are not "autobiographical": in Unsworth's case, you have to sell the book, not the author. He has lived in Greece and Turkey, Finland and Italy, and his abiding subject is the influence of landscape and history on human relations - not the kind of thing people often write magazine articles about. In person, he is diffident, apologetic, and the very opposite of bombastic. He avoids rather than seeks the limelight, and was dreading - as many authors dread - his upcoming round of public appearances. "You meet people you'd probably like if you met them in different circumstances," he explains, "but you find yourself trapped in this ... in this ... well, you know." He shrugs.

Still, he has put together a handsome and coherent body of work which is nearly always admiringly reviewed. He is extremely good-natured about the slightly faint praise with which I greeted his last novel ("Oh, I've had worse - a lot worse") and already intrigued by the reception being granted his new one, After Hannibal. In some ways it is quite a departure for him: it has a contemporary setting, in a place (Umbria) where he lives, and deals with matters - restoring a house, for instance - about which Unsworth has fresh memories. The inspiration came not from libraries, but from looking out the window. Inevitably, it is being widely read as a travel book, a sulky, dystopic version of the typical Brits-in-Tuscan- paradise myth. This, alone, might be enough to gain him the wide readership he plainly deserves: perhaps it can be sold as an allegory about the Blairs on holiday. As Peter Mayle proved, we British simply love this kind of thing; and the fact that After Hannibal is by no means a chatty journal about the ups and downs of Umbrian life, but a serious dramatisation of unsuccessful relationships, will probably not deter us.

The book is odd in not having a plot, as such. It features a number of different couples who have, for one reason or another, sunk their savings into the Umbrian dream. They are connected by a dusty neighbourhood road that becomes, as it has become for a thousand generations of Umbrians, something to squabble over. The interloping couples find their private differences thrown into an unsettling relief by these enduring quarrels, and the narrative glides between them, lighting on their various failings. In a sense, the most rooted of the characters is the historian, whose feeling for the country is fully informed by a knowledge of the blood that has been spilled over these pretty fields - from Hannibal onwards; but he pays for this preoccupation by losing his wife to a lover in Turin.

It is a comedy, but scarcely a happy one - a comedy of errors. There is one proper villain, a swindling English builder-from-hell called (unfortunately) Mr Blemish, who is eager to prey on gullible newcomers. And the man presiding over all the follies is the lawyer in whose chambers the characters tend to wind up.

He stands - explicitly - for the courteous face of malign motives: he puts bad behaviour into nice words, and makes a game of it. In 217BC, Hannibal's Libyans and Iberians lured the Roman legions on to the marshy fringe of Lake Trasimeno and massacred them. In Unsworth's Umbria, little has changed but the weapons. People still lure, taunt, betray and murder one another. The landscape seems to command it.

At first sight, the world it conjures up is rather different from the one that inhabits Unsworth's previous books. Morality Play was a medieval pageant set in the gloomy, trackless forests and murky castles of northern England. And Sacred Hunger was a horrifying saga suggested by the dank, fatal cargo holds of Liverpool freighters. It was, as they say in the trade, Unsworth's "breakthrough" book, but it had an unusual and extremely literary provenance.

"I went to Liverpool as a writer-in-residence at the University," he remembers. "I was the first and last one they ever had, I think. Anyway, I'd come from Cambridge, and I was shocked at first by how dilapidated and deprived the city was. And then there was the highly politicised nature of the university, which was rather a new thing for me. And one way or another I got so involved that I didn't write anything for a year, and then I couldn't. It was awful. For 15 months I was blocked, the first time I'd ever had that.

"I became neurotic - I couldn't sleep. It's a terrible thing because you don't know whether 'it' will ever come back, and you don't even know what 'it' is. And you lose energy and just feel that you're failing in everything. The only cure is to just do it, however bad, and that's what I did. I wrote a novel called Sugar and Rum, which I don't think was a particularly good novel, maybe. But it was about a blocked writer, and what he was failing to write was a book about slavery. He got so bogged down in the appalling nature of the slave trade that he couldn't write the book. And in the process of doing that I became interested myself, and I suppose that in a way Sacred Hunger was the book he wanted to write but couldn't."

In stark contrast to the brutal worlds described in these books, Umbria is, at least, sunny. There are clematis flowers and linnets. But Unsworth is quick to explain that the three works are connected - almost to the point of being a trilogy by the theme of justice. "In Sacred Hunger, it's about what is lawful in the general consensus of opinion of the time, compared to what is urged by the individual conscience.

"In Morality Play, justice is an attribute of power, a poetical weapon, something imposed by the strong upon the weak. And here, in the character of the lawyer, Mancini, it's to do with the difference between justice and law. To Mancini, justice is a question of form or shape, almost an aesthetic concept - not a question of right and wrong, more a question of balance."

Unsworth talks in a formal manner that seems both charming and old-fashioned. Indeed, if After Hannibal is marred, it might be that the modern setting feels, if anything, a touch dated. He freely admits this to be a worry and a danger. He never intended to flee England ("It's been just an accident, really") but he married a Finnish woman and lived in Helsinki, and then moved to Umbria, Italy, because England looked too pricey. He is the first Unsworth not to have gone down the Durham mines - his father went underground when he was 13 - and he is a devotee (from afar) of the English landscape, "but living in Italy as I do," he says.

"We're happy there, very happy - maybe too happy. But I do sometimes feel too far from everything. And one's sense of the English language can be a bit affected. I don't read English newspapers and I watch Italian television. The only English I hear is the World Service. So I don't know the language of the street, and while I've never been what you might call street-credible as a writer - I haven't really needed to be - I can feel the remoteness of all that."

This must be why, in After Hannibal, people still "run" cars and call the landscape "heavenly". And it is noticeable that even in his own speech, Unsworth is unusually formal and elaborate. Even just chatting, he unfurls sentences full of long, subordinate clauses spinning on their commas. On the subject of his being an expatriate, he says: "I think that what I miss, and I don't think now at my age I'll ever acquire it, in Italy or anywhere else, however well I learn Italian - and even there I have a long way to go, is the ability to know immediately, from the merest inflection of a voice, or movements or mannerisms, what kind of people you are dealing with, as you do only with your own compatriots."

Not many people since Dryden, we might think, have injected so many parentheses into a sentence without losing the thread altogether. But Unsworth has, after all, spent the last few years first in the 18th century (for Sacred Hunger) and then in the Middle Ages (Morality Play), where people could say things like "forsooth" without anyone laughing. And this tense, deliberate syntax does give a striking steeliness to the conversations in After Hannibal.

People choose their words carefully, and so are properly damned when they choose the wrong ones: misquotation plays a key part in the unravelling of one relationship. The emblematic relationship in the book, a long-married English couple, comes to grief when the man is unnecessarily beastly to the neighbouring peasants, whom he has just bestead in a local land dispute. His wife is horrified by his unfeeling response, and we know that this will be the end of their affair.

"It was one of the things I thought of when I began the book," says Unsworth. "The idea that this sort of a revelation can come in a relationship after so many years. It can be delayed for a long time, for 40 years, but it's a killer when it does come. She's been aware of fundamental differences of sensitivity between them, but it doesn't really come into focus until this moment. And it's incurable, a rift like that. You can dislike your husband or wife for a long time without realising that it's dislike you're suffering from, especially if you have a gift for humility, for self-abnegation. And, of course, what provokes it all in the book is the move to Italy. They buy the house to bring them closer together, but it only reveals the rat."

After Hannibal, in the end, is a rather pessimistic book. It is not ironic that there are snakes in arcadia: what else would you expect? "The real thief of dreams," the tricky lawyer reflects at the end, "was generally not the one you feared but the one you trusted." In a very deft way, Unsworth has peeked behind the manners of a 2000-year-old civilisation and found the same fierce rivalries and mean spirals that have been causing trouble in these parts for centuries. "It's such a strong feeling," he says. "I've had it nowhere else. In Greece, the past is all around you, but there is also this strong sense of loss. But here - I mean, in Umbria - the total humanisation of the landscape is inescapable. Everything is still going on." At one point in the novel, someone hacks some ivy off a tree by severing the root. But he knows that the scars on the trunk will never fade.