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place in post-war England, and they specifically bring in references to Tolkien's legendarium (at that time largely unpublished) and treats these references as primary fact within Lewis's fiction.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:
Simon Tolkien
Simon Tolkien notably disagreed with the policy of his grandfather's estate in regard to "The Lord of the Rings" films. When Christopher Tolkien issued a statement that the "Tolkien estate would be best advised to avoid any specific association with the films", Simon Tolkien broke ranks, offering to cooperate with the filmmakers, stating "It was my view that we take a much more positive line on the film and that was overruled by my father." Following up a 2001 interview with the "Independent", Simon in 2003 gave interviews to the "Daily Telegraph" and other media in which he discussed his strained relationship with his father, describing it as a permanent breach. However, they have since reconciled.