You can find a more detailed version of what happened with a quick Google search, but we'll give you the condensed version. Originally planned to be a musical entitled "The Kingdom Of The Sun," the film had Roger Allers ("The Lion King") directing with Sting contributing six songs, in what was an Incan retelling of Mark Twain's "The Prince & The Pauper." However, the film wound up falling behind schedule, and worried about early poor test scores, and fearing the story wasn't original enough, Mark Dindal ("Cats Don't Dance") was brought in to try and liven up the story. With a release date looming, the pressure increased on Allers and when he asked for an extension of six months to year, he was denied, and he quit the picture.
Disney then put the project on hold, temporarily assigned the animations to work on the "Rhapsody In Blue" sequence for "Fantasia 2000," and Dindal along with producer Randy Fullmer and writers Chris Williams and David Reynolds, completely reworked the project and story into the movie you know today. Because Sting had written specific songs for the first version, they all had to be dropped, with only one left that usable (all the songs are available on the soundtrack).
Needless to say it was a dramatic tale, with lots of tension and headbutting between the creative teams and the studio. However, Sting's wife Trudie Styler -- a movie producer and filmmaker -- was there to capture it all from beginning to end, and the result is "The Sweatbox." The feature length documentary has been kept out of site by Disney for years, with no release on home video, though it did screen at TIFF in 2002. And we doubt it will be released any time soon (if ever). However, someone has upload the whole thing to YouTube and it's a pretty fascinating look at what really goes on behind closed doors. Watch it below before it gets yanked.