What is the title of the 1977 book edited by Christopher Tolkien from J.R.R. Tolkien’s writings?

The 1977 book edited by Christopher Tolkien from J.R.R. Tolkien’s writings is The Silmarillion.

The Silmarillion was published posthumously by George Allen & Unwin on 15 September 1977. Christopher Tolkien prepared the text from a large and complicated body of drafts, revisions, notes, and alternative versions left by his father, who died in 1973. The work presents the mythology and history behind The Hobbit and The Lord of the Rings.

Its sections include the creation account in the Ainulindalë, the divine history of the Valaquenta, the First Age narratives of the Quenta Silmarillion, the story of Númenor in the Akallabêth, and a brief account of the Rings of Power. The book therefore covers a much broader span than Tolkien’s best-known novels.

The Silmarillion is not a conventional single-volume novel. It is a compiled mythology, and Christopher Tolkien’s editorial decisions shaped the form in which modern readers encountered it.