Say what you want about the Harry Potter movies, it’s undeniable that the Harry Potter cast is pretty stacked. From Michael Gambon to Alan Rickman and Ralph Fiennes to Julie Walters, each and every one of them nails their characters, and even the kids are good (something not always guaranteed).

Despite there being more Harry Potter characters than stars in the sky, though, not every actor got a chance to appear in the fantasy movies, much to their disappointment. One such actor was the comedy movie legend Robin Williams who really wanted to be in the Potter films.

According to the Potter director Chris Columbus Williams actually approached him about playing the fan favourite Defence Against the Dark Arts teacher Remus Lupin. “I had a conversation with Robin Williams, who wanted to play Lupin,” Columbus told GamesRadar. “It was very difficult for me to say, ‘It’s all British. There’s nothing I can do.’”

When Columbus refers to “all British”, he’s referring to the author’s strict stipulation that all the adult cast be played by British actors. That meant no Americans could appear in the family movies and cost the film some pretty big-name actors and possibly the greatest director ever.

Yes, Steven Spielberg was reportedly interested in adapting the Potter books to the big screen. Spielberg, however, wanted to make it an animated movie and apparently planned on using an American cast, so it was decided he wasn’t right for the project.

It’s interesting to think of what could have been had Spielberg been allowed to helm the series, but we’ll never know. If you love the Wizarding World, check out our guide to the best Harry Potter villains, or if you’re looking for something to watch on the small screen, we have a list of the best fantasy series for you to enjoy.