J.R.R. Tolkien was C.S. Lewis’s close friend in the Oxford literary group known as the Inklings.
The Inklings were an informal group of writers and scholars who met in Oxford, especially at The Eagle and Child pub and in Lewis’s rooms at Magdalen College. Their discussions included works in progress, mythology, Christianity, poetry, and imaginative literature.
Tolkien and Lewis became friends during the 1920s. Lewis helped encourage Tolkien’s confidence in his fiction, while Tolkien’s ideas about myth and language influenced Lewis’s literary conversations. Both men were also members of the English faculty at Oxford for part of their careers.
Other important Inklings included Charles Williams and Owen Barfield. Dorothy L. Sayers was a different writer and was not one of the core members of the Inklings, making her a plausible but incorrect choice.