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place in post-war England, and they specifically bring in references to Tolkien's legendarium (at that time largely unpublished) and treats these references as primary fact within Lewis's fiction.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:
C. S. Lewis
As a teenager, Lewis was wonder-struck by the songs and legends of what he called "Northernness", the ancient literature of Scandinavia preserved in the Icelandic sagas. These legends intensified an inner longing that he would later call "joy". He also grew to love nature; its beauty reminded him of the stories of the North, and the stories of the North reminded him of the beauties of nature. His teenage writings moved away from the tales of Boxen, and he began using different art forms, such as epic poetry and opera, to try to capture his new-found interest in Norse mythology and the natural world. Studying with Kirkpatrick ("The Great Knock", as Lewis afterwards called him) instilled in him a love of Greek literature and mythology and sharpened his debate and reasoning skills. In 1916, Lewis was awarded a scholarship at University College, Oxford. Within months of entering Oxford, the British Army shipped him to France to fight in the First World War. In one of his letters, Lewis cited that his experience of the horror of war, along with the loss of his mother and his unhappiness in school, were the bases of his pessimism and atheism.