The History Of The Lord Of The Rings Collections series by J.R.R. Tolkien consists of 4 books, published between 1988 and 1992. The series begins with The Return of the Shadow.
The Later Silmarillion Collections series by J.R.R. Tolkien consists of 1 book, starting in 1993. The series begins with Morgoth's Ring: The Legends of Aman.
The Middle-Earth Universe series by J.R.R. Tolkien consists of 3 books, published between 1992 and 1999. The series begins with Tolkien's World: Paintings of Middle-Earth.
The Tales of Middle Earth series by J.R.R. Tolkien consists of 3 books, published between 2007 and 2022. The series begins with The Children of Húrin (By: Christopher Tolkien).
The The History of Middle-Earth series by J.R.R. Tolkien consists of 8 books, published between 1983 and 2018. The series begins with The Book of Lost Tales, Part One.
The The Lord of the Rings series by J.R.R. Tolkien consists of 5 books, published between 1937 and 1974. The series begins with The Hobbit.