Bilbo Baggins celebrated his 111th birthday at the party described in The Fellowship of the Ring.
The birthday celebration takes place in Hobbiton, where Bilbo gives a large party for his relatives, neighbors, and friends. His birthday is notable because he is “eleventy-one,” Tolkien’s playful expression for 111. The event also marks his unexpected departure from the Shire and the transfer of the One Ring to Frodo.
Bilbo’s age is sometimes confused with Frodo’s age. Frodo is much younger when Bilbo leaves, although hobbits come of age later than humans and can live for many decades. Bilbo’s long life reflects Tolkien’s portrayal of hobbits as a people with unusually substantial lifespans.
The party is more than a celebration: it begins the chain of events that leads to the quest to destroy the Ring. Tolkien uses an ordinary village gathering to introduce the Shire, its customs, and the contrast between domestic comfort and the dangers beyond it.