'Mary Poppins' is a Disney Classic that reminds us all to never fully grow up and keep our family close. Little did we all know what Walt Disney went through to get permission to make the film.

In 'Saving Mr. Banks,' set to premiere in December, Tom Hanks plays Walt Disney and shares the story of how Disney gained the permission of children's author P.L. Travers to create a film based on her book.

The star-studded cast is not likely to disappoint avid Disney fans - after all, with Tom Hanks, Emma Thompson, Collin Farrell and more, how could you?

Watch the trailer here: