Which posthumous J.R.R. Tolkien book was edited by Christopher Tolkien and published in 1977?

The posthumous J.R.R. Tolkien book edited by Christopher Tolkien and published in 1977 was The Silmarillion.

The Silmarillion presents the mythology and history behind Tolkien’s fictional world, beginning with the creation of Eä and continuing through the history of the Elves, Men, and other peoples. It includes stories from the First Age, including the tales of Beren and Lúthien, Túrin Turambar, and the fall of Gondolin.

Tolkien worked on related material for decades but did not complete a final version suitable for publication before his death in 1973. His son Christopher selected, arranged, and edited the surviving manuscripts. The resulting book was published four years later by George Allen & Unwin.

Readers sometimes mistake The Silmarillion for a conventional novel. It is instead a collection of interconnected legends, annals, genealogies, and narrative sections. Christopher Tolkien later published additional volumes showing how the stories changed across his father’s drafts.