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).
Theophilus Johnson
Theophilus or Theo Johnson was born on 23 August 1836 at Tottenham in Middlesex, the third son of George Johnson, a well-to-do wax refiner from the City and his wife, Ann, daughter of John Josse of Spitalfields. He was the grand-uncle of Laurence Bertrand Johnson, the good friend of C. S. Lewis. Theo was apprenticed as a stationer and printer, eventually starting his own letterpress printing business.