Elwin Ransom
Elwin Ransom may be based on C. S. Lewis' friend J. R. R. Tolkien ("Elwin" means "Elf friend" in Anglo-Saxon), though he seems to have autobiographical elements. In "That Hideous Strength" Ransom, with his royal charisma and matter-of-fact breezy acceptance of the supernatural, appears less like Tolkien than like Charles Williams (or some of the heroes in Williams' books).
Great Haywood
The village was home to the newly married Edith Tolkien, wife of famous author J. R. R. Tolkien, from March 1916 to February 1917. She moved to the village to be close to his camp on Cannock Chase. J. R. R. Tolkien himself lived in Great Haywood in the winter of 1916-17.