Middle-earth
Another example is C. S. Lewis's "Space Trilogy," in which Earth is also called Middle-earth. Lewis's novels are situated at the approximate time of World War II, with the last novel, "That Hideous Strength," taking place in post-war England, and they specifically bring in references to Tolkien's legendarium (at that time largely unpublished) and treats these references as primary fact within Lewis's fiction. Merlin, of King Arthur fame, is treated as a successor to the Atlantis magic found within "Numinor" (Lewis's unintentional misspelling of Númenor), and similarities can also be found in the Quenya name for Númenor, which is "Atalantë," and Lewis specifically references the earth as Middle-earth twice, both in Chapter 13, "They Have Pulled Down Deep Heaven on Their Heads". Lewis's borrowings came directly from Tolkien himself: they were close friends and shared each other's literary creations. Lewis encouraged Tolkien to persevere with his Middle-earth writings.A small selection from the many books about Tolkien and his created world:
Tolkien family
Baillie Tolkien (née Klass) is the second wife of Christopher Tolkien. She was born in Winnipeg on 10 December 1941 to Dr. Alan Klass and his wife Helen. Alan Klass (1907–2000) was a surgeon and a distinguished member of the Faculty of Medicine at the University of Manitoba. Baillie attended McGill University and the University of Manitoba from which Baillie received her B.A. in 1962. She received her M.A. from St Hilda's College, Oxford in 1964. Her first husband was Brian Knapheis, a Rhodes Scholar from Winnipeg, to whom she was briefly married. While as Baillie Knapheis, she worked as a secretary, first to J.R.R. Tolkien and then to Isaiah Berlin. She married Christopher Tolkien on 18 September 1967. She has two children with Christopher. Their son Adam Reuel Tolkien was born in 1969, and their daughter Rachel Clare Reuel Tolkien was born in 1971. After the death of J.R.R. Tolkien, his letters written to his children were edited by Baillie for publication. The contents of the book were released in a 1976 book titled "The Father Christmas Letters", in which Baillie is credited as the editor. In the 1976–77 exhibition of paintings held at the Ashmolean Museum in Oxford and afterwards at the National Book League in London, Baillie contributed a short introduction to the catalogue.