In a post on Facebook, Peter Jackson announced that they will re-title the third film of The Hobbit from There And Back Again to The Battle of the Five Armies. The former title was a reference to the name of the collection of Bilbo’s memoirs as collected in the Red Book of Westmarch, the “source” of the stories that J.R.R. Tolkien recounts in his Middle-earth books (the first movie’s title, An Unexpected Journey, is a similar reference.) When it was just two movies as originally planned, the title made more sense, but now with how the story is split, it was appears to make more sense to take on a name referring to a latter section of the book.
Here is the full post.