The title of J.R.R. Tolkien’s posthumously published 1977 work assembled from his mythology is The Silmarillion.
The Silmarillion was edited and arranged by Tolkien’s son Christopher Tolkien and published four years after J.R.R. Tolkien’s death. It presents a compressed history of the world from its creation through the First Age and into later events. The book is built from many writings that Tolkien revised repeatedly across his lifetime.
Its central section, the Quenta Silmarillion, recounts the wars over the three Silmarils, jewels made by the Elf Fëanor. Other sections include the Ainulindalë, describing creation through music, the Valaquenta, describing the Valar and Maiar, and the Akallabêth, about Númenor. The final section concerns the Rings of Power and the Third Age.
The book is not a conventional single novel. Christopher Tolkien selected, edited, and sometimes connected texts so that readers could follow the mythology, making The Silmarillion different in form from The Hobbit and The Lord of the Rings.