13 books in series

The History of Middle-Earth

The History of Middle-Earth is a 13-book series with 13 released primary works first released in 1983 with contributions by J.R.R. Tolkien and Christopher Tolkien.

The Book of Lost Tales: Part One
The Book of Lost Tales, Part II
The Lays of Beleriand
The Shaping of Middle-earth
The Lost Road and Other Writings
The Return Of The Shadow: The History of the Lord of the Rings, Part One
The Treason of Isengard: The History of The Lord of the Rings, Part Two
The War of the Ring: The History of The Lord of the Rings, Part Three
Sauron Defeated
Morgoth's Ring
The War of the Jewels
The Peoples of Middle-earth
The History of Middle Earth Index