The literary club with C.S. Lewis, etc. was formed after Tolkien’s school years. While he was at King Edward’s School in Birmingham and then at Oxford, he and three of his closest friends formed the Tea Club of the Barovian Society (TCBS), based upon their mutual love of languages and heroic tales (like Beowulf). I have always found it fascinating that Tolkien created the elvish languages first, and then created the Middle-earth mythology around his invented languages to explain who was speking the languages and why. The story came second, the languages first.