The Silmarillion (Quenya: [silmaˈrilːiɔn]) is a book consisting of a collection of myths and stories in varying styles by the English writer J. R. R. Tolkien. It was edited, partly written, and published posthumously by his son Christopher in 1977, assisted by Guy Gavriel Kay, who became a fantasy author. It tells of Eä, a fictional universe that includes the Blessed Realm of Valinor, the ill-fated region of Beleriand, the island of Númenor, and the continent of Middle-earth, where Tolkien's most popular works—The Hobbit and The Lord of the Rings—are set. After the success of The Hobbit, Tolkien's publisher, Stanley Unwin, requested a sequel, and Tolkien offered a draft of the writings that would later become The Silmarillion. Unwin rejected this proposal, calling the draft obscure and "too Celtic", so Tolkien began working on a new story that eventually became The Lord of the Rings.
The Silmarillion has five parts. The first, Ainulindalë, tells in mythic style of the creation of Eä, the "world that is." The second part, Valaquenta, gives a description of the Valar and Maiar, supernatural powers of Eä. The next section, Quenta Silmarillion, which forms the bulk of the collection, chronicles the history of the events before and during the First Age, including the wars over three jewels, the Silmarils, that gave the book its title. The fourth part, Akallabêth, relates the history of the Downfall of Númenor and its people, which takes place in the Second Age. The final part, Of the Rings of Power and the Third Age, tells the history of the rings during the Second and Third Ages, ending with a summary of the events of The Lord of the Rings.