The History of Middle-earth

The History of Middle-Earth, is a series compound by twelve volumes, published in 1983 to 1996, that analyze the works of J.R.R. Tolkien. The book was edited and compiled by his son, Christopher Tolkien. These books are extremely detailed, Christopher Tolkien wrote the books based the annotations of his father. But some texts continue not published, they continue in the libraries of Bodleian and Marquette University, and in particular hands, like in "Elvish Linguistic Fellowship".
The first five books discuss about the ancient history of The Silmarillion and relational texts. From the sixth to the ninth, the books discuss about the history of Númenor in the formation of The Notion Club Papers. The books ten and eleven back to the Silmarillion, with the "Annals of Beleriand" and the "Annals of Aman". The twelfth book discuss about the creation of Lord of the Rings' appendix.
The books are: