The Greatest Influence of Lewis on Tolkien

Lewis and Tolkien both loved Norse mythology and William Morris fantasies. Lewis's greatest influence on Tolkien was to get Tolkien in two of his stories to shift from a Norse view of mythology to a more Christian view of mythology. In the Silmarillion, which Tolkien just never could quite finish, it's like a retelling of Beowulf. And that's what Tolkien uses in both the Hobbit and the Lord of the Rings,. contrary to everything else he wrote in the Silmarilion.