While Peter Jackson’s Lord of the Rings film trilogy has received much (deserved) acclaim, many fans of the original books have complained that the movies took too many liberties and cut out too much from Tolkien’s story. But if he had gone forward with his original plan during the development process, Jackson would have crammed in all three books into a single two hour-film!
Peter Jackson first considered tackling J.R.R. Tolkien’s Middle-Earth story as a film project when he was in the process of wrapping up 1996’s The Frighteners. He did some research on who owned the movie rights to the books and approached Miramax studios about financing the production of a single film based on The Hobbit and two films based on The Lord of the Rings (Ralph Bakshi’s 1978 animated adaptation of the latter was also intended to span across two films, but only one of the two made it to the screen). Miramax secured the rights to The Lord of the Rings, but could not wrest the rights for The Hobbit away from United Artists. Jackson, though, decided to go forward with his adaptation of Tokien’s trilogy and would stick to his plan to condense it into two films (as a side note: Universal offered Jackson the King Kong remake at this same time, but plans for that stalled and he proceeded with The Lord of the Rings movies).
Jackson and his writing partners then began to hammer out the scripts which resulted in a 147 page screenplay for the first film and 144 pager for the second (just slightly above the average for a typical Hollywood production). As the project progressed, though, Miramax balked when they learned that the cost would likely run double the $75 million that had originally budgeted for the two films. This resulted in their suggestion that the two screenplays be condensed into one. The studio then threw together a treatment that would have crammed the entire Lord of the Rings trilogy into a single two-hour movie! Peter Jackson, though, was unhappy with their truncated version claiming that it ended up “cutting out half the good stuff”.
He then began to shop the idea around to other studios and when he approached New Line Cinema they asked why he wasn’t planning on filming it as three movies, just like the original books. This led to him striking up a deal with that studio which resulted in the three films that quickly turned into instant genre classics upon their release. And while those films still took some liberties with the original story and had to condense and/or cut out parts, just imagine how much less satisfying the two film adaptation, or worse the single film version, would have been!
Source: Wikipedia