Trivia: The characters of Prince John and King Richard are based on real people. Their mother, Queen Eleanor of Aquitaine, really did prefer Richard over John and all her other children (although John didn't really lapse into fits of whining and sucking his thumb.) John eventually became king after Richard's death.
Trivia: The Sheriff of Nottingham was originally written to be a goat. It was later changed to a wolf as wolves seem more villainous.
Trivia: In addition to the party scene already mentioned, some of the dance steps are from The Aristocats. And if you remember from The Aristocats, when they are having their party, some of the animals in Robin Hood look like the cats. Seems like they like to use the same dance routine for many films.