The Silmarillion is the posthumously published 1977 book edited by Christopher Tolkien from his father’s writings.
J.R.R. Tolkien died in 1973 without completing a definitive version of the book. Christopher Tolkien assembled and edited material from drafts, notes, and later revisions, working with fantasy author Guy Gavriel Kay. George Allen & Unwin published the result in 1977.
The book presents the mythology and history of Tolkien’s world, beginning with the creation of Eä and continuing through the First Age and later events. Its central narrative includes the creation of the Silmarils by Fëanor and the wars against Morgoth.
The Silmarillion is not a conventional sequel to The Lord of the Rings. It is a composite work shaped from texts written across many decades, so its editorial construction differs from Tolkien’s completed novels.