What are the initials represented by the three R’s in J.R.R. Tolkien’s name?

The three R’s in J.R.R. Tolkien’s name represent Ronald Reuel.

Tolkien’s full name was John Ronald Reuel Tolkien. “John” was his first name, “Ronald” was his middle name, and “Reuel” was his second middle name. He was commonly known publicly by the initials J.R.R. Tolkien rather than by a shortened form of his full name.

“Reuel” was also the name of his father, Arthur Reuel Tolkien, and came from a family naming tradition. Tolkien’s name is sometimes expanded incorrectly because the repeated initials can suggest two separate middle names beginning with R in an arbitrary order. The accepted expansion is John Ronald Reuel Tolkien, and the name is distinct from his brother Hilary’s full name, Hilary Arthur Tolkien.