The Silmarillion is Tolkien’s posthumously published mythology book edited by his son Christopher.
Christopher Tolkien edited The Silmarillion from his father’s extensive manuscripts, and George Allen & Unwin published it in 1977, four years after J.R.R. Tolkien’s death. The book gathers stories about the creation of the world, the angelic Valar, the Elves, and the great conflicts of the First Age.
Its central narrative includes the history of the Silmarils, three jewels made by the Elf Fëanor. Their theft by Morgoth drives much of the tragedy in the Quenta Silmarillion. The book also contains material about Númenor and the Rings of Power, connecting its earlier legends to The Hobbit and The Lord of the Rings.
The Silmarillion is not a conventional novel completed in one continuous form by Tolkien. It is a carefully arranged posthumous work based on writings that changed over many decades. Christopher Tolkien’s editorial decisions made the collection readable while preserving its mythic, historical character.