The History of Middle-Earth series of books chart the process and detail that Tolkien put in to creating the world of Middle-Earth. These books were posthumously published (and edited) by Christopher Tolkien. They contain drafts, notes and some of the thinking that Tolkien engaged in when creating his fantasy world.
- The Book of Lost Tales, Part I (published in 1983)
- The Book of Lost Tales, Part II (published in 1984)
- The Lays of Beleriand (published in 1985)
- The Shaping of Middle-Earth (published in 1986)
- The Lost Road and other Writings (published in 1987)
- The Return of the Shadow (published in 1988)
- The Treason of Isengard (published in 1989)
- The War of the Ring (published in 1990)
- Sauron Defeated (published in 1992)
- Morgoth's Ring (published in 1993)
- The War of the Jewels (published in 1994)
- The Peoples of Middle-Earth (published in 1996)