J.R.R. Tolkien’s middle name was Reuel.
He was born John Ronald Reuel Tolkien, and the initials in his pen name stand for John Ronald Reuel. “Reuel” was not a conventional family surname; it came from Tolkien’s family history and was used as one of his given names.
Tolkien is usually identified by his initials because his full name is long and distinctive. The middle initial is especially familiar to readers because it appears in the author credit for The Hobbit, The Lord of the Rings, and his other works.
The name should not be confused with Ronald, which was his second given name and the name by which he was commonly known during much of his life. Tolkien’s full name is recorded in biographies and reference works, making Reuel a specific biographical fact rather than a fictional name from Middle-earth.