The Silmarilli were three flawless gems created by Fanor, the most talented of the Elves, and they contained the final Light of the Two Trees of Valinor. However, Morgoth, the first Dark Lord, seized the gems and placed them beneath his iron crown, which was guarded in the impregnable stronghold of Angband in the north of Middle-earth.
The Silmarillion is the account of Fëanor and his kindred's revolt against the gods, their exile from Valinor and return to Middle-earth, and their futile fight against the great Enemy. It is the original drama upon which the characters of The Lord of the Rings reflect, and in which some of them, such as Elrond and Galadriel, took part.
The book also contains other shorter writings, including the Ainulindalë, a Creation tale, and the Valaquenta, which describes the nature and abilities of each of the gods. The Akallabêth relates the story of the collapse of the great island kingdom of Númenor at the end of the Second Age, while Of the Rings of Power gives the history of the momentous events at the end of the Third Age, as told in The Lord of the Rings.
Tolkien was unable to publish The Silmarillion because it continually developed throughout his life, so he left it to his son, Christopher Tolkien, to edit the work from numerous manuscripts and bring his father's great vision into publishable form, thus completing the literary accomplishment of a lifetime. This unique edition reprints this essential first move toward planning the posthumous publication of Middle-earth, as well as the start of a distinguished forty-year career from Christopher Tolkien, and more than twenty works honouring his father's legacy.