“The Enchantress of Florence” (Random House, 368 pages, $26) is a “Harry Potter”-ish restoration project of great intelligence and remarkable egoism, both of which are characteristic of its author. Although he sets his novel in the Florence of the Medicis and Machiavelli, in the Mughal court of Akbar the Great, and at the height of the Ottoman Empire, Salman Rushdie hasn’t written just any pedantic, research-obsessed “historical novel.” Instead of trying to give us the past as it really was, he’s tried to produce the very kind of “historical romance” that might have been passed among French, Italian, English, and Mughal courtiers of the late 16th and early 17th centuries, a book to give them hours of “much languid play … in the curtained afternoons.” There are pirates, shipwrecks, hidden princesses, lost heirs, and magic mirrors. There are giants, epic battles, and potions that “facilitate one hundred consecutive ejaculations.” “In Andizhan, the pheasants grew so fat that four men could not finish a meal cooked from a single bird,” begins one chapter, and that note of superlative excess gives the tone of the whole.

Sir Salman (now a valiant English knight!) appears to be entering the lists to compete with younger novelists of adventure. Recent American novels such as “The Adventures of Kavalier and Klay” and “The Fortress of Solitude” accomplished the elevation of comic book superheroes into intellectual respectability, so much so that it now often seems a young man can only announce himself a proper and popular literary novelist by flaunting his adolescent tastes in print. But none of the current generation of American “boys’ own” novelists has dared to reach back as far beyond his own adolescence to the youth of the novel itself. Take that, Batman; here comes the original caped crusader, Arcalia of the Enchanted Lance!

It’s an audacious gesture, but it also makes a lot of sense for a novelist with a gift for the extraordinary. A return to the age of chivalry, Rabelais’s carnival, and Pico Della Mirandola’s “Oration on the Dignity of Man” has fitted Mr. Rushdie with appropriately heroic and larger-than-life subjects for his larger-than-life prose. His more recent novels, by contrast, were often mismatches, testing the patience of readers by attempting to ennoble celebrity musicians (“The Ground Beneath Her Feet”), fashion models (“Fury”), and contemporary global elites (“The Moor’s Last Sigh,” “Shalimar the Clown”). Our democratic skepticism meant that it was hard to indulge the aristocratic idea that some characters we might meet on a street in New York or Bombay really could be more equal than others. That problem has been solved in this novel. Everyone in “The Enchantress of Florence” is painted with Mr. Rushdie’s broad brush, but at least the canvas is suitably enormous.

History, alas, is harder to redraft. The present shades any attempt to re-create the past, and “The Enchantress” comes weighted down with references and even a bibliography. It’s larded with an encyclopedia of familiar pleasures for connoisseurs of Western and Eastern Renaissance literature and fans of Italo Calvino’s “Invisible Cities.” That is to say it’s a rhapsody woven from earlier works, a pastiche, a considerate pillaging of the past. Not so much plotted as patterned in concentric circles of repeating motifs, the novel embroiders on the usual Rushdian themes — chiefly the costs and benefits of uprooting oneself for the sake of a chance to improve one’s position. Like all romances for grown-up people, “The Enchantress” is intended as an allegory.

The novel’s real hero, of course, is Mr. Rushdie himself, and its adventures are his own preoccupations transposed: his imagination fighting a losing battle against time; his horn sounding as he guards the pass to his threatened kingdom — of cosmopolitan, “self-fashioning” open borders, robust secularism, irreverent argument, true love, and 100,000 pleasures — against the armies of resentment, that “No Fun League” of Puritans, nationalists, religious fanatics, penitents, weepers, feminists, psychoanalysts, and, er, the occasional literary critic.

“The Enchantress” opens with the arrival of a yellow-haired farangi, a foreigner, at the court of that most enlightened of despots, the Grand Mogul, Akbar, sometime around 1590. (No actual dates are provided in the book, and time generally is treated in a cavalier fashion, as are certain historical events; a strict chronology would have one of the heroes leading the campaign against Vlad the Impaler when he was 8 years old.) The Mughal setting cleverly reminds Western readers of what we most want for contemporary Central Asia and the Middle East: a multicultural empire that tolerates inquiry and theological debate — although, in this case, never dissent. At the same time, the stranger’s journey comes to seem like a distant mirror and inversion of a younger Mr. Rushdie’s passage from a bitterly divided India to the freethinking capitals of the West. The stranger, too, has traveled from a ravaged sectarian society, only it’s Reformation Europe, torn between Catholics and Protestants.

The foreigner comes riding in an open cart, like a disguised Lancelot in the “Roman de la Charette”; he introduces himself as the English ambassador but is really Italian, or part Italian. Dressed in a magical motley coat won off “Shalakh Cormorano,” a Jewish merchant of Venice, he is a harlequin, a jongleur, a rogue, a teller of tales, and a sorcerer. He has a story for the emperor’s ear alone, the story of the enchantress that will alter the balance of the court’s power.

The confidence man is only one of a series of alter egos running through the novel. Akbar takes the stage as a lonely absolute ruler who has built a magnificent city with an entirely artificial water supply, and who creates his favorite wife from nothing more than the text on the page in front of us, “dreamed up … in the way that lonely children dream up imaginary friends.” Reality is, in fact, largely conditional upon the emperor’s wishes, and the limitations to his power — like his refusal to execute his rebellious son — are of Akbar’s own making. His power increases his license to imagine, and the wide latitude of that imagination increases his power. In his isolation and solipsism, the emperor recalls no one so much as the novelist himself, and it’s no surprise that Akbar is the novel’s most fully realized character.

It is difficult to ignore the element of autobiography in these fairy tales, since Mr. Rushdie has always been something of a knight of identification: In “Midnight’s Children,” the narrator is a magical child on whose body and mind a miniature version of India’s fate from independence to Indira Gandhi’s emergency is mysteriously played out; “The Satanic Verses” featured Saleem Sinai, a character with many biographical and physical resemblances to his author, whose body becomes the center of an ongoing, unresolved theological struggle between Islam and poetry, angels and devils; “Rock and roll and I share a birthday,” Mr. Rushdie once began a lecture. He puts himself at the beginning of everything — “I is India,” his writing seems to suggest — yet he can be in so many places at once because he also distributes himself generously. There’s an arrogance to this, of course, but also a certain fragility, as though without these larger associations he is nothing but a blank mirror. Mr. Rushdie wants to recount the history of modern India, the origin of Islam, and now the course of modern history, but he does this by creating portmanteau characters who all come to seem like versions of himself. Ultimately, there’s too little of the rest of the world in those portrayals, and the man himself comes to seem to exist for the sake of the grand movements he represents. His novels, too, as they accumulate, now seem like records of a mind seeking the meaning of its own importance.

“The Enchantress” is at least a complete enough allegory to reveal the author’s Achilles’ heel. The novelist appears in a different disguise as the court artist Dashwanth, a brooding melancholic who, while painting the story of the enchantress, falls in love with her and transforms himself into a miniature figure in the border of his own masterpiece: “Instead of bringing a fantasy woman to life, Dashwanth had turned himself into an imaginary being … If the borderline between the worlds could be crossed in one direction … it could also be crossed in the other. A dreamer could become his dream.”

Mr. Roth is an editor at the journal n+1.