The book The Lord of the Rings is made up of three books, The Fellowship of the Ring, The Two Towers and The Return of the King. It followed the book, The Hobbit.
They named the movies after the books.
What’s not to understand?
Oh yeah, why did it three long movies to cover one thin book?
Amen!
these movies are fun to watch.
However, I will always return to Middle-Earth by reading the books to be truly entertained.
Probably money had a lot to do with it. Three films, especially from source material which is known and beloved by millions of aging Tolkien fans from the sixties and seventies (like yours truly) as well as a younger generation who know Jackson’s LOTR and crave more of Middle Earth, is a three year cash stream on a gargantuan scale.
Because it included information found in the LotR Appendices, expanded events hinted at in the Hobbit (book), and included events spoken of in LotR (books) when Gandalf spoke to Frodo and others about past events, etc., etc., etc.
I suspect interpolations from the Book(s) of Lost Tales, Unfinished Tales, and a smidge of the Silmarillion. Since PJ does not have film rights to those books, He’ll never say so :p