The Silmarillion is an account of the Elder Days, of the First Age of Tolkien's
world. It is the ancient drama to which the characters in The Lord of the Rings
look back, and in whose events some of them such as Elrond and Galadriel took
part. The tales of The Silmarillion are set in an age when Morgoth, the first
Dark Lord, dwelt in Middle-Earth, and the High Elves made war upon him for the
recovery of the Silmarils, the jewels containing the pure light of Valinor.
Included in the book are several shorter works. The Ainulindale is a myth of the
Creation and in the Valaquenta the nature and powers of each of the gods is
described. The Akallabeth recounts the downfall of the great island kingdom of
Númenor at the end of the Second Age and Of the Rings of Power tells of the
great events at the end of the Third Age, as narrated in The Lord of the Rings.