4 books in series

The History of The Lord of the Rings

The History of The Lord of the Rings is a 4-book series with 4 released primary works first released in 1984 with contributions by J.R.R. Tolkien and Christopher Tolkien.

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
The End of the Third Age: The History of The Lord of the Rings, Part Four