On the morning of Oct. 29, 1618, 1982 -- the feast days of St. Simon and St. Jude, when all London would turn out for the Lord Mayor's Show -- Sir Walter Ralegh breakfasted heartily, smoked tobacco and mounted with smiling countenance a scaffold in the Old Palace Yard at Westminster. From it, in the presence of great crowds, he made his final declaration, reviewing his past life and avouching his innocence of the charges upon which he had been convicted. "I say again to you most solemnly: I was never a traitor. If I speak false, let the Lord blot out my name from the Book of Life!" With eyes open -- he had refused the blindfold -- Ralegh bade the trembling executioner perform his duty, crying out with a great shout of command, "Strike, man, strike!" It was the last, and perhaps the most impressive, assertion of Sir Walter Ralegh's indomitable will.

At the hearing held the previous day to reaffirm the sentence passed 15 years earlier, the attorney general, Sir Henry Yelverton, had summed up, "Sir Walter Ralegh has been a statesman, and a man who in regard of his parts and quality is to be pitied. He had been as a star at which all the world has gazed. But stars may fall . . . Nay, my Lords, they must fall, when they trouble the sphere wherein they abide!" Adventurer and intellectual, warrior, poet and lover, Ralegh was a star that troubled his sphere. Accordingly, he fell.

A writer who set out to improve upon such language and such human drama would be foolish indeed. Robert Nye is no fool but a gifted English novelist, poet and journalist best known here for his rumbustious "Falstaff," offering the fat reprobate's memoirs, as purportedly dictated in his 81st year and (so the title rather archly puts it) "transcribed, arranged and edited in modern spelling by Robert Nye." In "The Voyage of the Destiny" he has wrought a complexly orchestrated novel of Ralegh's last journey, in a spare, masculine, sometimes eloquent modern style which eschews mayhaps and forsooths, yet can accommodate authentic firsthand materials--Yelverton's peroration, the 13 stanzas of Ralegh's poem "The Lie" (never mind that Nye misdates it; that's novelistic prerogative), and all 10 brief chapters of "Sir Walter Ralegh's Instructions to his Son and to Posterity."

The subject has evidently haunted Nye for some time: A decade ago he edited, and sensitively introduced, a slender anthology of Ralegh's poetry. The verses that conclude that volume, Sir Walter's last written words, evoking time --

Who in the dark and silent grave,

When we have wandered all our ways,

Shuts up the glory of our days

-- poignantly bring to a close the journal that Nye has invented for his hero.

In the novel, the story of Ralegh's days begins when he sails as admiral of a fleet of 14 ships and three pinnaces manned by a thousand volunteers: a few gentlemen excepted, "the very scum of the world, drunkards, blasphemers and suchlike." The admiral's flagship was the Destiny, built of solid English oak for the occasion, and named by Sir Walter himself, no doubt with conscious irony, for he must have known that this would be his last voyage. He was then in his sixties, and by the standards of the time, an old man.

His brief was to bring back gold from the mines of Guiana. Ralegh had been there before, taking part in the recurring European quest for El Dorado, the legendary South American city where gold and precious jewels in abundance were supposedly to be had for the taking. In 1596 he had published a pamphlet describing the expedition, "The Discovery of the Large, Rich, and Beautiful Empire of Guiana, with a relation of the great and golden city of Manoa (which the Spaniards call El Dorado)." Ralegh had come back with tiny specimens of gold-bearing ore. Now he was prepared to try again; his last, desperate gamble.

For 13 years he had been a prisoner in the Tower, where, a captive Prospero, he had conducted scientific, medical and alchemical experiments in his makeshift laboratory, and written the first and only volume of his vast -- and vastly popular -- meditative universal history, "The History of the World." No matter that the capital charges on which he had been tried were trumped-up; in law he was a dead man. In March of 1616 Ralegh was given a reprieve -- not a pardon -- to outfit himself for a second Guiana expedition. The royal coffers were bare, and King James was seduced -- as Ralegh had been -- by the delusion of a whole mountain of readily transportable gold.

Spain, however, claimed the entire Orinoco region, and Ralegh had perforce to pledge his life that he would not encroach upon Spanish possessions or harm any Spanish subject. The golden mountain that might have extenuated trespass did not exist; the destiny of the voyage was foredoomed. After tempest, desertion, mutiny and disease, one vessel, the Destiny itself, made it back to port with 22 survivors. Disaster had struck early. While Ralegh lay feverish aboard his anchored flagship, a scouting party that included his eldest son Wat, nephew George and trusted lieutenant, Sir Laurence Keymis, had gone upriver on the Orinoco to scout for the mine. In a clash at the garrison of San Thome', Wat and the Spanish governor were killed; unforgiven by his master, Keymis committed suicide. Once home, Ralegh attempted to slip off to France, only to be betrayed by his kinsman, Sir Lewis Stukeley, who had warmly embraced him and kissed him on the cheek. Stukeley would be rewarded by the Exchequer and reviled as Sir Judas.

Ralegh's journal, set down for his little son Carew, also recounts the voyage of his own history. Reminiscence harks back to Ralegh's service in the Irish campaign during the long hot summer of 1580. He was then 26. The next year at court, as Queen Elizabeth -- 20 years his senior -- crossed a splashy road on her way to the Tiltyard Gallery, Ralegh performed his mythical gesture of plucking his cloak from his shoulders and spreading it over the mire for his sovereign to walk dry-shod across. She now knew who this handsome young courtier with the broad Devon accent was. The dance was his. Before long he became the royal favorite; monopolies, grants and estates came his way. Disgrace too, when the queen discovered that Ralegh was the secret lover of one of her maids of honor. James I, who succeeded Elizabeth, had passions for the hunt and his catamites, and an aversion to Sir Walter Ralegh.

The dance Ralegh danced (so the novel would have us believe) led to Elizabeth's private apartments. There, even as they disported themselves naked, the Virgin Queen remained virgin still. This is the promised dust-wrapper revelation about "the courtier whose strange relationship with Queen Elizabeth I has never before been fully explored or explained." But we don't turn to a novel for historical disclosures, any more than we go to "Amadeus" to discover what took place between Salieri and Mozart. We look, rather, for truths of the imagination, and in this respect "The Voyage of the Destiny" offers richer rewards than Peter Shaffer's clever melodrama.

There is a third voyage as well. This is the interior journey that takes form "by shapes looming out of the fog, by shouts in the storm." The challenge is considerable, for to his contemporaries, as to posterity, Ralegh was a great enigma, this man who was so "damnably proud," as Aubrey of the "Brief Lives" describes him. Nye's Ralegh is no giant and no god, but vulnerably human. "I suffer from this strange disease, you see," he writes to his wife Bess. "My attitude to you is a symptom of it. How to define that sickness? It has no name. It drives me always to reject the real, the immediate, unless my circumstances give me a cause to bewail my lot. For more than half my life I have lived in such a way as to maintain a distance between myself and the objects or the persons of my love."

So he does with his wife and with Carew. In the end he sees himself as another Hamlet who counterfeited madness to escape a king's suspicion, and then became what he pretended to be. I think he's wrong about Hamlet, but how quarrel with a character in a novel? As a fictional character this Ralegh is sufficiently persuasive, and that is no mean novelistic feat.

The reviewer is director of the Center for Renaissance and Baroque Studies at the University of Maryland. His books include "Shakespeare's Lives" and "Shakespeare: The Globe and the World."