J.R.R. Tolkien’s first published book-length work about Middle-earth was The Hobbit.
The Hobbit, or There and Back Again, was published in 1937. It follows Bilbo Baggins as he leaves the Shire with Thorin Oakenshield and a company of Dwarves to reclaim the Lonely Mountain from Smaug.
The book began as a children’s fantasy adventure, but it introduced important elements later connected to the darker history of The Lord of the Rings. These include Bilbo’s discovery of the Ring, Gollum, and the geography surrounding the Misty Mountains.
The Silmarillion was published after Tolkien’s death, in 1977, while The Lord of the Rings appeared in three volumes from 1954 to 1955. Unfinished Tales was also a posthumous collection.