The Silmarillion has five parts. The first, Ainulindalë, tells 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, is a brief account of the circumstances which led to and were presented in The Lord of the Rings.
The book shows the influence of many sources, including the Finnish epic Kalevala, Greek mythology in the lost island of Atlantis (as Númenor) and the Olympian gods (in the shape of the Valar, though these also resemble the Norse Æsir).