Tolkien’s legendarium is the body of J. R. R. Tolkien’s mythopoeic writing that forms the background to his The Lord of the Rings, a high fantasy novel which is widely considered to be his magnum opus. Tolkien worked and re-worked the components of his legendarium throughout his adult life, a period of more than 50 years; the earliest drafts, published in The Book of Lost Tales (1983), date to 1916, with poems, paintings and nomenclature related to it going back to 1914. […]
Unlike “fictional universes” constructed for the purpose of writing and publishing popular fiction, Tolkien’s legendarium for a long period was a private project, concerned with questions of philology, cosmology, theology and mythology. It has been considered a “pure mythopoeia”.[…]
He called his collection of nascent stories The Book of Lost Tales. This became the name for the first two volumes of The History of Middle-earth, which include these early texts. The stories employ the narrative device of a mariner named Eriol (in later versions, an Anglo-Saxon named Ælfwine) who finds the island of Tol Eressëa, where the Elves live; and the Elves tell him their history.