The beloved 1964 Disney film Mary Poppins is known has one of the greatest children’s films of all time. But the first-time fans will get to see how the classic film almost never came to be. Disney’s new film, Saving Mr. Banks, will take a never-before-seen look into the 20-year battle between Walt Disney (played by Tom Hanks) and Mary Poppins author P.L. Travers to acquire film rights to her beloved children’s books. The film will also dip into the duo’s difficult relationship during pre-production of the motion picture in 1961. Production for the blockbuster — which stars big name celebrities like Tom Hanks, Emma Thompson and Colin Farrell – will begin Wednesday Sept. 26 in LA and will continue over the next two months at “key locations” including Disney Studios in Burbank and Disneyland in Anaheim. A release date has not yet been set.