The Lord of the Rings, J.R.R. Tolkien’s great work of modern mythology, was forged by three wars. The first began 100 years ago, a hell of mud and fire. The second was its successor, a time of contending totalitarian visions. The third has in some respects never ended, pitting East against West, religion against religion.

As truly as it did George Orwell’s Nineteen Eighty-Four, the Cold War most fully shaped Tolkien’s vision. But Tolkien also opposed two larger worlds that were not coextensive with the empires on either side of the meaningfully named Iron Curtain: the green agrarian world of the English countryside—the Shire—against the dark, satanic mills that lay always just over the horizon. It is clear which Tolkien preferred; his villains are the trolls and goblins who clear-cut forests and reduce mountains to deep holes in the ground, his heroes, the steady country people who stand firm against the dark overseers of mines and vast cities.

Tolkien, a veteran of the western front, began LOTR in the interstices between the world wars, having enjoyed unexpected success with a juvenile novel called The Hobbit, published in 1937. As publishers will, his asked for a sequel. It took him nearly twTolkieno decades to produce it. Tolkien, a scholar of Germanic and Celtic languages and medieval literature, had been assembling great mounds of work notes for an epic cycle, and he brought that considerable research to bear on what emerged—an amalgam of Icelandic sagas and Persian monster tales, wedding the Welsh Mabinogion to the Wagnerian Ring Cycle and the Kalevala and Beowulf, with dashes of Old Norse, Catholicism and William Morris–style fairy tales thrown in for leavening.

LOTR is famously a book of books, drawing on a vast library for background and inspiration; Tolkien even borrowed from his philological work for the Oxford English Dictionary to add details to the story, a compliment repaid when his coined word mithril entered the dictionary in 1976. But LOTR is also a book of friendship, and more particularly, the friendship—the fellowship—that evolves from service in war. The primary virtues are constancy and loyalty; it is always the dark armies that break and run, always the little men of the Shire who forget that they are afraid long enough to do the impossible, which is the very definition of heroism, and a particularly English view of it at that.

Tolkien stole time for the book whenever he could over the next two decades, and the result was massive: a manuscript of nearly 10,000 pages in several variations. Tolkien never intended it as a trilogy, but The Lord of the Rings was published in three parts all the same, broken down in order to keep the size and price manageable; the three parts were released in 1954 and 1955 in Britain and in the latter year in the United States. Taken together, it has gone on to be the second best-selling novel in English—not bad for a medieval allegory brought into our own time, and it’s one that, in book and film forms alike, continues to inspire.

Gregory McNamee is a contributing editor at Kirkus Reviews.