The Silmarillion was edited and released after J.R.R. Tolkien’s death by Christopher Tolkien in 1977.
The Silmarillion presents stories about the creation of Eä, the history of the Elves, and the wars against Morgoth in the First Age. It is not a conventional novel with one continuous narrative. Instead, it combines mythic accounts, legends, genealogies, and historical-style sections covering the long history behind The Hobbit and The Lord of the Rings.
J.R.R. Tolkien died in 1973, leaving a large and sometimes contradictory body of drafts and notes. Christopher Tolkien selected, arranged, and edited material for publication, with assistance from Guy Gavriel Kay. The book appeared in 1977. Because it was assembled from unfinished writings, its editorial history differs from that of Tolkien’s published novels. Unfinished Tales, another posthumous collection, followed in 1980.