The Silmarillion is actually Tolkien's first book and also his last. In origin it precedes even The Hobbit, and is the story of the First Age of Tolkien's Middle Earth. It shows us the ancient history to which characters in The Lord of the Rings look back, talk, rhyme and sing about. Tolkien worked on it, changed it, and enlarged it throughout his entire life. It was edited and published posthumously by his son Christopher Tolkien, with the assistance of fantasy fiction writer Guy Gavriel Kay to reconstruct some major parts.