Prologue: The View from the Janiculum Weary of dodging gelato-eaters and rushing motorini, a lucky walker in Rome may be lured out of the teeming streets of Trastevere by the prospect of the upward-sloping paving stones of the sicamore-shaded Via Garibaldi. To the right, a sidestreet dead-ends in flights of well-worn stone steps, bordered on one side by fortifications built by a third-century emperor to repel barbarous Germanic tribes. The staircase ascends, alongside crumbling bricks overgrown with wildflowers and canary-grass, to a piazza dominated by a striking monument in luminous travertine limestone. The Fontana dell''Acqua Paola is a confection of the high Baroque, built around five niches--divided by columns of red granite, and topped by high-perched griffins, lines of stone-cut Latin, and a gossamer iron cross--out of which water gushes into a cerulean basin, as shallow as it is enticing. Built by a seventeenth-century Pope, it is fed by the same ancient aqueducts that once filled Trastevere''s naumachia, an artificial lake where the Emperor Trajan staged mock naval battles using galleys rowed by real slaves. Taxi drivers know it simply as the fontanone, the big fountain. Of Rome''s two thousand municipal fountains, it is the only one in which citizens are permitted to bathe during summer heat waves. The Fontana dell''Acqua Paola, however, is merely the backdrop to a far more impressive spectacle.

Crossing the paving stones of the semi-circular piazza, the fortunate stroller approaches a curved stone balustrade, which projects like a proscenium over the most sumptuous of playhouses. Just beyond the high canopies of thin-trunked umbrella pines, the first metropolis of the world unscrolls to the limits of peripheral vision. Ecco: Roma. In the foreground, quadrilaterals of weathered stucco in hues of ochre and pink form a Cubist jumble, jostling around a bend in the Tiber that snags Trastevere, the most ancient and authentic of Rome''s rioni, or central neighbourhoods, like a bishop''s crozier. Across the river, the hemispheric roof of the two-millennia-old Pantheon, the largest dome in the world until well into in the twentieth century, protrudes from Rococo cupolas, a concrete barnacle cemented fast to the medieval and Renaissance city. And, white as sun-bleached baleen, the Brescian marble of the Vittoriano, that pretentious monument to the earthiest of Italy''s kings, rises against the Impressionist smear of blue on the horizon, the foreboding Sabine and Alban hills. The Latin satirist Martial, who owned a villa near the crest of the Janiculum, wrote of this view: "From here you can see the seven lordly hills, and measure the whole of Rome." The only reminders that this is the second decade of the twentieth-first century are the cellphone masts that bristle from certain strategic eminences, and the occasional contrail of an airplane that scumbles a sky notably unscraped by towers of glass and steel.

One hundred years ago, a young man, newly arrived from New York, leant on this same balustrade and, contemplating his uncertain future, consoled himself with the enduring glory laid out before him. Humans and their problems came and went, he mused, but Roma--the Urbs Aeterna, the Caput Mundi, the Città Eterna--would always abide. Its persistence across the centuries seemed to offer a salutary rebuke to an unhealthy obsession with the present. The young man was wrong about Rome. It has never been exempt from history. From the Janiculum, "the balcony of Rome," observers have watched the flames that leapt up from the Temple of Jupiter as Sulla sacked the Forum, the cannonballs that burst in the Piazza Barberini after French troops dislodged General Garibaldi from the Villa Aurelia, and the columns of smoke that rose from the rubble of the San Lorenzo district after its carpet-bombing by Flying Fortresses in the dying days of the Second World War. And on that autumn day in 1920, the cast was already assembling in the streets below for the next revolutionary act in the city''s ongoing drama. In the salons and cafes, war-maddened poets, drunk on velocity and technology, were calling for the burning of St.

Peter''s Basilica and the razing of the Colosseum. Across the river in Testaccio, red flags were flying from the roofs of workshops occupied by laborers hoping to bring the Bolshevik revolution to Italy. Black-shirted war veterans, who were even then terrorizing peasants and workers throughout the country, were setting their sights on Rome as the ultimate prize in a new battle for Italy. None of that, of course, could be perceived by the young man leaning on the balustrade perched on the Janiculum. As he turned towards the Fontana dell''Acqua Paolo, to walk the hundred yards back to his new home at the American Academy in Rome, this visitor from the New World was conscious only of being young, happy and alive in the timeless, the unchanging, the Eternal City. Except that everything was about to change, for him and for everyone he knew. Between the ancient cobblestones, modernity''s most corrosive doctrine was already sending down deep roots. Fascism''s time had come.

Only a rare few would perceive the danger, and begin to resist. Rome, Italy, Europe, and the world would never be the same.