“The Silmarillion” is a collection of myths and legends of Middle-earth, describing the history of Arda from its creation through the perspective of the Valar and the elves. If in “The Lord of the Rings” the events unfold at the end of the Third—beginning of the Fourth—Age of Middle-earth, then “The Silmarillion” tells of events from the creation of the world up to the beginning of the Third.
The work was published posthumously by J.R.R. Tolkien’s son, Christopher.