J.R.R. Tolkien’s The Lord of the Rings was first published in three volumes.
George Allen & Unwin issued the work in three parts because paper shortages and postwar publishing costs made a single large book impractical. The Fellowship of the Ring appeared in July 1954, The Two Towers in November 1954, and The Return of the King in October 1955.
Although the story has three published volumes, Tolkien described it as one novel rather than a trilogy. Internally, he divided it into six books plus appendices. The volume titles are now so familiar that readers often call the work a trilogy, but that label refers to its publication structure rather than three unrelated stories.
Different editions have sometimes been printed in one or two physical books, especially in paperback. Those formats do not change the original publication arrangement. The three-volume structure also helped establish the sequence in which most readers first encountered the journey from the Shire to Mount Doom.