Richard Madden has said Sir Kenneth Branagh helped him transform into Prince Charming for the big screen.
The Scots actor plays the prince in the film version of Cinderella, due out next year, which also stars Helena Bonham Carter and Cate Blanchett.
Sir Kenneth has directed the movie adaptation of the famous folk tale.
Richard said: "He's another person that I've watched for years and can't help but look up to, so getting to work with one of your heroes is something I'm very grateful for.
"To be directed by an actor is always interesting. They just do it in a different way. I don't know if it's better or worse, so I had an absolute ball working with Ken."
Richard, who played Robb Stark in Game Of Thrones, added: "I don't think I'd be able to pull off a character such as the Prince if Sir Kenneth Branagh wasn't guiding me through it."
The screen star, who has signed up for period drama Klondike, said it will be strange following Game Of Thrones as a viewer rather than an actor.
"I can't wait to watch it. I'm still very good friends with a lot of the other actors in the show, especially Kit Harrington. We meet up all the time and he's like: 'Oh I filmed this thing last week for episode four...' and I'm like, 'Don't tell me!'," he said.
:: Klondike is on Discovery Channel on Thursdays.