The Silmarillion is a collection of J. R. R. Tolkien’s mythopoeic works, edited and published posthumously by his son Christopher Tolkien and the writer Guy Gavriel Kay in 1977. This book describes the universe of Middle-earth within which The Hobbit and The Lord of the Rings take place. The History of Middle-earth is a twelve-volume examination of the writing and revisions of The Lord of the Rings and The Silmarillion by looking into J. R. R. Tolkien’s rough drafts and by commentary by Christopher Tolkien.

The Silmarillion comprises five parts.

1. Ainulindalë, tells of the creation of Eä
2. Valaquenta gives a description of the Valar and Maiar, the supernatural powers in Eä.
3. Quenta Silmarillion, chronicles the history of the events before and during the First Age.
4. Akallabêth, relates the history of the Downfall of Númenor and its people, which takes place in the Second Age.
5. Of the Rings of Power and the Third Age, is a brief account of the circumstances which led to and were presented in The Lord of the Rings.