Marco Polo was not much given to modesty. In the prologue to his fabulous “Travels,” he brags that no man “since the creation of Adam” had seen or searched out so many wonders as he had. There was a certain defiance in his boast: The more precise and detailed his descriptions of Persia and India and China, the less people believed him. He had set out for the East in 1271, when he was only 17. His destination was the Mongol court of Kublai Khan, a figure of dread to Europeans. He spent almost two decades at that court, mastering the local languages and becoming a favorite of the Khan. He returned to Venice in 1295, rich in goods and brimming with anecdotes. But his tales struck his fellow citizens as preposterous. Children taunted him in the street with cries of “Messer Marco, tell us another lie!”

In his splendid “Marco Polo: From Venice to Xanadu” (Knopf, 415 pages, $28.95), the well-known biographer Laurence Bergreen offers not so much a conventional biography as the lively reconstruction of a supreme adventure. To accomplish this, he has assimilated a vast body of scholarly literature in several languages. For the original sources, whether in Chinese or Mongolian or Persian, he has relied on experts from London to Ulan Bator, Mongolia, and Beijing. He has woven this complicated, and often conflicting, material into a dramatic and beautifully written narrative. Best of all, he has himself retraced Polo’s elusive footsteps in Mongolia and China so that as we read, we often seem to be but one step behind the inquisitive Venetian. The marvellous plates, which include color reproductions of medieval miniatures as well as spectacular photographs of the Silk Road and other exotic sites, enhance this unexpected feeling of immediacy.

Polo’s “Travels” — or “Il Milione” (“The Million”), as it is known in Italian, in reference either to a Polo family nickname, Emilione, or to the “million lies” contained in the book, it isn’t clear — isn’t an easy book to follow. As Mr. Bergreen remarks, it sometimes reads as if a pile of loose pages had been dropped and carelessly scooped up. Polo hops from topic to topic. At one moment he describes hunting for porcupines, at another the meticulous protocols of the Mongol court. This scattered effect is due in part to the fact that Polo’s account was taken down, years later, when he languished in a Genoese prison, by a fellow inmate, Rustichello of Pisa, who wrote, and embellished, it in Old French. Manuscripts in other languages soon proliferated. There was even a “public copy” kept chained to the Rialto Bridge to satisfy the Venetian appetite for Polo’s “tall tales.”

Mr. Bergreen is very good at sorting out these complexities. Like most scholars today, he believes that Polo’s account is essentially accurate. Where he skimps on details, Mr. Bergreen deftly fills in the background. In discussing the courtesans of Quinsai, whose free and easy sexual practices intrigued Polo, Mr. Bergreen quotes from ancient Chinese “sex primers” to show, in quite explicit detail, the exotic pleasures available to the impressionable young Venetian. Again, in describing local Chinese reactions to their Mongol overlords, Mr. Bergreen brings in apt quotations from the poetry of the time, as when one poet laments, “Northwards, far as the eye can reach, our conquered land seems endless.” This lends a human accent to Polo’s sometimes rather dry observations.

Polo, like Julius Caesar, always refers to himself in the third person in his “Travels,” and this gives a false impression of aloofness. In fact, he was a passionately curious traveler. A consummate merchant, he loved things and knew their value. He had a keen eye for precious stones, but he wasn’t above disclosing where to find “the best melons in the world” (northeastern Iran). He traversed unfamiliar realms with all the gusto of a shopper let loose in the grand bazaar. His avid curiosity was allied with a remarkable open-mindedness. He admired Kublai Khan, seen as the scourge of the earth, as a wise and enlightened ruler, and, furthermore, dared to present him as such. Thrown into contact with Buddhist or Muslim beliefs or the shamanistic Christianity of the great Khan, Polo remained unruffled. His sheer fascination with the endless variety of the world left no room for the abstractions of dogma.

Polo’s travels took him to the eastern limits of the world. But they were also journeys to the boundaries of the human imagination. It was his “Xanadu” that, in Mr. Bergreen’s words, “would inflame Coleridge’s opium-besotted cortex” when he sat down to write “Kubla Khan.” Never mind that the “stately pleasure dome” was in reality the summer hunting camp of the great Khan and, like all nomadic structures, was both “collapsible and portable.” There was something strangely contagious about Polo’s restless itch to discover the world. Barely two centuries after Polo’s death in 1324, Columbus was inspired by the “Travels” to set out for a legendary Cathay. On all four voyages, Columbus took with him his own heavily annotated copy of Polo’s great book. He was sailing in the wrong direction but in the end it didn’t matter. For him, as for Marco Polo, the factual and the legendary had become one.

eormsby@nysun.com