The Lord Of The Rings, Behind The Scenes

A dispute with his publishers, George Allen & Unwin, led to the book being offered to Collins in 1950. Tolkien intended The Silmarillion (itself largely unrevised at this point) to be published along with The Lord of the Rings, but A&U were unwilling to do this. After his contact at Collins, Milton Waldman, expressed the belief that The Lord of the Rings itself "urgently wanted cutting", he eventually demanded that they publish the book in 1952. They did not; and so Tolkien wrote to Allen and Unwin, saying, "I would gladly consider the publication of any part of the stuff."
For publication, the book was divided into three volumes: The Fellowship of the Ring (Books I, The Ring Sets Out, and II, The Ring Goes South,) The Two Towers (Books III, The Treason of Isengard, and IV, The Ring Goes East,), and The Return of the King (Books V, The War of the Ring, and VI, The End of the Third Age, plus six appendices). This was due largely to post-war paper shortages, as well as being a way to keep down the price of the book. Delays in producing appendices, maps and especially indices led to the volumes being published later than originally hoped — on 21 July 1954, on 11 November 1954 and on 20 October 1955 respectively in the United Kingdom, and slightly later in the United States. The Return of the King was especially delayed. Tolkien, moreover, did not especially like the title The Return of the King, believing it gave away too much of the storyline. He had originally suggested The War of the Ring, which was dismissed by his publishers.
The books were published under a profit-sharing arrangement, whereby Tolkien would not receive an advance or royalties until the books had broken even, after which he would take a large share of the profits.