Middle-earth is the central location of Tolkien's legendarium, a fictional mythology about Earth's distant past. The Lord of the Rings and The Hobbit are included in his legendarium. Tolkien's posthumous publication of The Silmarillion and The History of Middle-earth series by his son Christopher Tolkien exposed his lifetime labor on the same legendarium, a process he referred to as "sub-creation." Among Tolkien's other published writings are philological dissertations, contemporary retellings of ancient tales, and original tales that he told his kids but which have nothing to do with the legendarium.
