The Weight of History : AFTER HANNIBAL.<i> By Barry Unsworth</i> .<i> Nan A. Talese/Doubleday: 250 pp., $22.95</i>

“Do you know the land where the lemon-trees flower?” Goethe wrote in a poem that helped shift the elevation angle at which the Romantics regarded earthly salvation. Instead of going upward to heaven, you went sideways to Italy.

Since then, untold hundreds of thousands have traveled from Northern Europe, the United States and elsewhere, not so much for the sun as to follow a grand line of beauty and aesthetic order that shifted from Greece to Rome, sheltered in the medieval abbeys and burst forth in the Renaissance. Above all, it went beyond works of art to show itself at the turn of a street, to blossom almond-white in a restaurant’s courtyard and to stretch over patterned hills, olive groves and terra cotta roofs, as if that same art had formed them all.

Increasingly, when the grand hotel gave way to the pensione and then to the dream of the perfect villa or a month’s apartment rental, the sense grew that you could do more than follow the line. You could join it; you could become part of the beauty. You could change your life, have breakfast in the painting, wash dishes in the three stanzas retained from college Dante. Literary adjectives would climb off the shelf and enlist as daily household help. “Crystalline” might overdo it, but water would be more than water when you turned the tap.

Or less--and when a plumber finally came, he might go away without fixing it, overcharge and get mysteriously angry. Baffling notices would slide under the door; a routine bank errand turn into an inexplicable crisis. The cheerfully talkative butcher would fling an indifferent piece of meat across the counter and go taciturn.

The literature of Mediterranean illusion and disillusion is vast. A lot is bad--most recently, the smarminess of Peter Mayles’ exploitative romancing about food and the picturesque in Provence. Much of it, honest enough, keeps to the ruefully light. But there is a literary tradition--a leading one, in fact--of great writing: Henry James, E. M. Forster, D. H. Lawrence, John Cheever, Penelope Fitzgerald and William Trevor are a few of the very different names that come to mind.

“After Hannibal,” by the British writer Barry Unsworth, is a vivid, sinuous, profound and entirely beguiling venture at squaring their same circle: How do we balance our need for the Mediterranean illusion, the reality in the illusion and the reality of that reality?

The first leads to an exploration of ourselves, the second to an evocation of the power of art and beauty over time--a power as real as war and plague. The third brings in the war and plague and confronts the first two with the harshness of how people actually struggle and live. We are ravished by the beauty of hill-town walls and facades; we do not know how to reconcile it with the smell of bloodshed so copiously in building, assaulting and defending them.

Unsworth weaves these things together in a polyphony as acrid as a Gesualdo madrigal and playful as a tavern catch. He interweaves the stories of four couples--two Italian, one English, one American--and a single German, who own small villas along a common dirt road in the Umbrian countryside outside Perugia. Each is there after some illusion or fulfillment. Each comes up differently against the consequences of history, stretching back 2,000 years and affecting, right to the present day, the way that people behave and the way the very grass blades grow.

Not far from the dead-end dirt road, Hannibal’s troops hid in the fogged-in hills above Lake Trasimeno and swept down to massacre the Roman legions, unfamiliar with the landscape and struggling in the lakeside marsh. Unfamiliarity with the landscape or, in the case of the Italians, with the history that seeps through it, is one of the themes that runs through Unsworth’s dazzling novel.

There is Harold Chapman, a blustering, prosperous English developer, and his art-loving wife, Cecilia. She had hoped that an Umbrian villa and lots of culture would bring them together; for Harold, acquiring culture is a war of conquest like any other. He gets into a feud with a peasant family--not in the least picturesque and quite as greedy as he--who wants him to pay for the collapse of their rickety wall after the Chapman’s construction trucks have rumbled through. When they hammer in stakes to block the road, Chapman sallies into Perugia to enlist Mancini, the lawyer.

There is Fabio, a former racing-car champion, and his male lover, Arturo, whom he has plucked from a life of prostitution. Benefaction and tyranny are hard to distinguish, though; Fabio insists on meticulous order and labor to embellish their small paradise of a villa. Outwardly compliant, Arturo seduces Fabio into signing the property over to him, arguing tax and other advantages. He then decamps and brings an eviction action. “I will kill him,” Fabio rages, but he too goes to Mancini.

There are the Greens, two retired American art teachers who have invested their savings in a broken-down villa, hoping to turn it into a retirement dream. They are hopelessly bilked by Blemish, an English con man who sets himself up in the vicinity as a kind of super-contractor.

Blemish and his stout wife are a wonderfully loving pair. After his day of swindles and hers of frying up rich pastries, they don Restoration costumes and play galumphing sex games. They are a high order of low comedy and sharp as shark’s teeth. Blemish’s dealings with the sweetly and insufferably innocent Greens are an agonizingly expert course in how to be fooled. Rallying eventually, they arrive at Mancini’s rapidly filling waiting-room--of which more in a moment.

Connected in a more ghostly fashion to the story is Ritter, a German translator who has broken down remembering his father, an army officer who took part in the Ardeatine Caves massacre of 335 Italian hostages. The father’s self-exculpatory explanations work like slow poison in a son whose profession is words. He labors to clear his five acres of scrub, a wordless image for his battle with the tangled lies of the past.

Finally there is Monti, a historian whose wife has just left him for another man. Puzzling out her betrayal, he pursues his research into the bloody and treacherous conflict of Renaissance Perugia with the papacy. Monti’s travels to nearby villages, in order to put together the story of the particularly carnivorous Baglioni family, is one of two silken threads that bind his neighbors’ stories together. The gentle Monti learns from the history he unearths; it teaches the futility of revenge and, instead of burdening his grievance, lightens it.

The second thread is provided by the much-solicited Mancini. Angelically devious, he leads his tormented clients through the entirely divergent complexities of Italian law and Italian practice. As a young man, he explains, legal solutions seemed to be straight lines. Not so; they are a web.

This benevolent spider bends his clients’ quests for linear justice through the prism of a millennial history. Law is not a sword in Italy--too many righteous causes have been pursued too long and horribly. Instead, it is a cloudiness, under cover of which one can devise advances, retreats, feints, traps and finally, if possible, a solution. The tactics he proposes are hilariously twisted, while serving, strangely, time’s long-drawn approximate justice.

Each of the stories achieves indeterminate balances of satisfaction and frustration, thanks in part to the lawyer’s tutelage and in part to that of a fortuitous earthquake. History (researched by Monti, applied by Mancini) and the unstable landscape: These are the regulators of the dozen turbulent and comically detailed passions that Unsworth has so finely set in motion.