Joining Stewart in the cast are Timothy Spall (Secrets & Lies), Sally Hawkins (The Shape of Water), and Sean Harris (Mission: Impossible – Fallout, Prometheus). The screenplay is by Peaky Blinders creator Steven Knight.
“Kristen is one of the great actors around today,” Larraín told Deadline. “To do this well, you need something very important in film, which is mystery. Kristen can be many things, and she can be very mysterious and very fragile and ultimately very strong as well, which is what we need. The combination of those elements made me think of her. The way she responded to the script and how she is approaching the character, it’s very beautiful to see. I think she’s going to do something stunning and intriguing at the same time. She is this force of nature.”
“I’ve seen movies from Kristen that are so diverse, it’s incredible, showing different layers and her diversity and strength as an actress," he continued. "We’re very happy to have her, she’s very committed. As a filmmaker, when you have someone who can hold such a weight, dramatic and narrative weight, just with her eyes, then you have the strong lead who can deliver what we are looking for.”
"The accent is intimidating as all hell because people know that voice, and it's so, so distinct and particular. I'm working on it now and already have my dialect coach," Steward revealed.
"In terms of research, I've gotten through two and a half biographies, and I'm finishing all the material before I actually go make the movie."
Stewart's portrayal of Diana follows Emma Corrin's breakout performance of the royal in The Crown's fourth season on Netflix. Australia's own Elizabeth Debicki will succeed her in the role in Season five, which will likely premiere in 2022.