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place in post-war England, and they specifically bring in references to Tolkien's legendarium (at that time largely unpublished) and treats these references as primary fact within Lewis's fiction.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:
Edith Tolkien
Edith first met Tolkien early in 1908, when he and his younger brother Hilary moved into 37 Duchess Road by their guardian, Fr. Francis Xavier Morgan of the Birmingham Oratory. At the time, Tolkien was 16 years old and Edith was 19. According to Humphrey Carpenter, "Edith and Ronald took to frequenting Birmingham teashops, especially one which had a balcony overlooking the pavement. There they would sit and throw sugarlumps into the hats of passers-by, moving to the next table when the sugar bowl was empty. ...With two people of their personalities and in their position, romance was bound to flourish. Both were orphans in need of affection, and they found that they could give it to each other. During the summer of 1909, they decided that they were in love."