A pavane is a stately dance, one with all its steps set out, with a clear beginning and a foreseen end . To my ear, the word itself sounds melancholy, with an air of plangency that fits this achingly beautiful novel perfectly. First published in 1968 and now reissued by Old Earth Books as a handsome large-size paperback, “Pavane” is one of the masterworks of modern science fiction, a book that has won the admiration of such contemporary giants of the field as Neil Gaiman , China Mieville , Terry Pratchett , Christopher Priest and William Gibson . On the cover — itself a striking example of Leo and Diane Dillon’s distinctive artwork — George R.R. Martin , author of “A Game of Thrones,” calls Roberts’s book “a masterpiece . . . one of the greatest alternate world stories ever told.”

Technically, “Pavane” is what science-fiction readers call a “fix-up,” that is, a novel constructed from a series of separately published but linked stories. In the book’s prologue, we learn that in 1588 an assassin murdered Queen Elizabeth I, and the Spanish Armada successfully planted the flag of Spain on English soil. In short order, all the Protestant nations of Europe were then overturned by a resurgent Catholic Church. As the subsequent centuries have rolled by, the world has remained largely medieval, the most advanced technology permitted by the Church being the steam engine. As Roberts writes, to some these “were years of fulfillment, of the final flowering of God’s Design; to others they were a new Dark Age, haunted by things dead and others best forgotten; bears and catamounts, dire wolves and Fairies.” Those fairies, or Old Ones, are particularly important as preservers of heretical ancient knowledge, so much so that in the middle of the 20th century, “rebellion was once more in the air.”

There are six stories, called “measures,” in “Pavane,” and together with a coda these cover roughly four generations. England itself speaks five major languages: “the Norman French of the ruling classes, Latin of the Church, Modern English of commerce and trade, the outdated Middle English and Celtic of the churls.” Small details — such as the sacking of Florence by the mercenaries of Pope Orlando — further remind us that history has gone down a different timeline. Roberts, however, focuses almost entirely on a single section of Dorset, the towns and countryside around the castle of Corfe Gate.

In “The Lady Margaret,” Jesse Strange inherits his family’s locomotive-based hauling business. From his story we learn of the papal bull of 1910, “Petroleum Veto,” which has forestalled the development of the gas engine. In “The Signaller” a young boy named Rafe undergoes apprenticeship in the secretive Guild of Signallers, which operates the network of semaphore towers by which information is transmitted around the country and to Europe. Another young man, in “Brother John,” is transformed by his encounter with the Court of Spiritual Welfare, better known as the Inquisition.

At one point in this last story, Brother John experiences that desideratum of nearly every alternate history: a vision of “our” world, the “real” world. “He saw the machines flying above the land, skimming like bubbles on the surface of the sea. He saw wonders; lightning chained, the wild waves of the very air made to talk and sing. All this would come to pass, all this and more. The age of tolerance, of reason, of humanity, of the dignity of the human soul.”

”Pavane” by Keith Roberts (Leo and Diane Dillon)

At their best, alternate histories focus on people, much like ourselves, who are trying to get on with their lives in a world that is subtly, or substantially, different from our own. Think of Philip K. Dick’s “The Man in the High Castle” or George Orwell’s “Nineteen Eighty-Four.” Throughout “Pavane,” Roberts’s overriding concern is with the fragile human heart. His stories are suffused with loneliness and longing, with hopes and the dashing of hopes. In “The White Boat,” a young girl pins her dreams of a better life on a mysterious sailing ship, feared by her father, that sometimes appears in the bay near her village. In “Lords and Ladies,” Jesse Strange’s free-spirited niece Margaret falls in with the aristocratic Lord Robert of Wessex, whose family owns the great castle of Corfe Gate. She, too, experiences unsettling visions in which places are somehow skewed and twisted, but her sense of being unstuck in time she attributes to the influence of the Old Ones, the Fairies. In the last full-length story, her daughter, the Lady Eleanor, will lead the armed uprising against the established order of things — and will be helped by the Fairies.

All the characters of “Pavane” are deeply sensitive, but Eleanor is also fiercely indomitable. At one point, she is kidnapped and one of her people cruelly murdered by supposed agents of the king and pope. In a level voice, she curses her captors in the five languages of England and promises them death. The kidnappers are unexpectedly thwarted, and Eleanor confronts their leader: “He tried to barter with her then, or beg his life; but she stared at him as if he spoke an unknown tongue. ‘Ask mercy of the wind,’ she said, almost wonderingly. ‘Beg to the rocks, or the great waves of the sea. Don’t come and whine to me . . . ’ ”

Roberts concludes “Pavane” with a somewhat problematic coda, one that compels the reader to think again about the action of the novel and of the Church’s role in it. He also suggests that history is governed by a kind of eternal recurrence, that once before, “beyond all the memories of men, there was a great civilization” that rose and flourished until there came “a burning, an Armageddon.” This Arnold Toynbee-like rise and fall of civilization, set against the backdrop of the Catholic Church, calls to mind Walter M. Miller Jr.’s comparably moving and provocative novel on this theme, “A Canticle for Leibowitz” (1960).

Some years ago, Anthony Burgess — himself no slouch as a writer of alternate histories and dystopian sci-fi — chose “Pavane” as one of the 99 best novels written in English since 1939. I would add that it is also one of the most thought-filled, a book with the glowing but somber majesty of a stained-glass window, constructed from the most disparate bits and fragments, from the tesserae of multiple lives. What’s more, Roberts creates considerable suspense throughout, and his prose can be frequently joyous and lyrical, especially in descriptive passages. And yet, despite its optimistic coda, one closes this book riven with a sweet sadness, as at the end of some great tragedy.

Dirda reviews each Thursday in Style and conducts a book discussion for The Post at wapo.st/reading-room.

PAVANE

By Keith Roberts.

Old Earth. 242 pp. Paperback, $17.