In "The Lord of the Rings," Bilbo Baggins is 111 years old when he throws his famous birthday bash. Tolkien describes it as Bilbo’s “eleventy-first” birthday, a playful hobbit expression meaning 111.
The party takes place in the Shire on September 22, the shared birthday of Bilbo and his younger cousin Frodo. Bilbo’s celebration is unusually elaborate, with a large gathering, fireworks supplied by Gandalf, and gifts for the guests. He uses the occasion to announce his sudden departure and vanish while wearing the One Ring.
The number is easy to confuse with Frodo’s age: Frodo turns 33 at the same party, which is the age when a hobbit comes of age. Bilbo’s age also marks the passage of 60 years since the beginning of his adventure in The Hobbit. In the film adaptation, Ian Holm plays the elderly Bilbo, while Elijah Wood plays Frodo.