What was the name of J.R.R. Tolkien’s fictional book of stories about the First Age?

The Silmarillion was J.R.R. Tolkien’s fictional book of stories about the First Age.

The work presents the mythology and history of Tolkien’s imagined world from its creation through the First Age. It includes the Ainulindalë, the Valaquenta, the Quenta Silmarillion, the Akallabêth, and the concluding account of the Rings of Power. The central First Age narrative follows the wars over the Silmarils, jewels made by Fëanor.

Tolkien did not complete a final publishable form of the book during his lifetime. His son Christopher Tolkien edited material from the manuscripts, and The Silmarillion was published in 1977. It is not the same book as Unfinished Tales, which collects separate narratives and essays from Tolkien’s legendarium.