The original publication of The Lord of the Rings was delayed for two reasons. Tolkien tried to get out of his obligation to his publisher, Allen & Unwin, because another publisher had agreed to his wish to use different colors of ink for different parts of the book. In particular, he wanted the writing on the Ring to be printed in red ink. That deal fell apart, and he went back to Allen & Unwin. The second reason was that he wanted The Silmarillion; which told the history of the Elves and of Aragorn's race, the Numenoreans; to be published alongside Rings. No publisher would agree to this, so The Silmarillion was not published until after his death.
