“We think we all know Diana’s story, but I always ask the question: what must it have been like for any person going through that experience – what she was thrown into at such a young age?” said Benjamin Caron, the director of the Fairytale episode of The Crown.

Therein lies the challenge of the third episode of the fourth series of Netflix’s royal drama. A dramatisation loosely based on the royal family (and all the more contentious for it), the episode’s central figure is Diana Spencer, who accepts Prince Charles’s proposal and moves from her Earl’s Court flatshare to Buckingham Palace in preparation for her new life as a princess.

The Crown’s blurring of fact and fiction becomes trickier with, “arguably, one of the most famous women in the world, a person about whom everyone has an opinion”, noted Caron at last month’s RTS event “Deconstructing the Fairytale”.

The episode is, arguably, a masterclass in storytelling, especially when the story is world-famous. The script was one of The Crown’s shortest, at just over 30 pages, which allowed a greater emphasis on the telltale details of this key moment in royal history.

Laden with visual metaphors, it lever­ages every aspect available to a director to depict the emotional journey behind Diana’s dramatic switch from her old life to the new – and to foreshadow the already-familiar events of her life as a royal.

“As a guiding principle, I like to focus on the anthropological weirdness of these people and this institution,” said Caron. “It always comes back to the slightly cold, bruising, hurtful, lonely, locked-up pain. I love focusing on that uncomfortable stuff, that piece of gravel in the shoe.

“[But,] across the season, we see that remarkable strength of character which Diana possesses grow, and that power and resilience she has to rise above it all.”

Joining Caron on the panel were production designer Martin Childs and hair and make-up designer Cate Hall, both integral to the episode. Emma Corrin, who played Diana in the show, had to pull out of the panel due to a last-minute scheduling conflict, but her casting was the first and biggest step in the process.

“Casting Diana felt like no easy task until we met Emma. Very Diana-like, she walked into the room and instantly captured everyone’s attention,” said Caron. “She had this strength, this incredible vulnerability, which is a hard thing to play without being clichéd.”

Corrin’s depiction, and the freedom that the lean script afforded, combine in a revealing scene in which Diana practises ballet alone. Inspired by a similar scene in Billy Elliot (directed by Stephen Daldry, also an executive producer for The Crown) and soundtracked by a haunting use of Song for Guy by Elton John, Diana begins in a rigid, taught fashion.

But, as the emotions get the better of her, “it breaks out into her expression of her character, her personality, of her trying to push out against the walls of the palace,” said Caron. “It’s raw, it’s emotional, it comes at a really difficult time for her, but it speaks volumes about her incredible ability to overcome.”

The scene was shot on a closed set, with loose direction. “I always talk about giving actors permission to fail, about allowing them to go further than they might do without the constraints of being judged,” said Caron. “It was just me and the camera, and we played Cher’s Believe. It didn’t matter because we were going to replace the music later on, but it was something Emma felt she could throw herself around the room to.”

This scene also highlights the role that production plays. For Corrin to be able throw herself around the room without restraint, her wig had to play its part by staying on and adding to the spectacle of her torment.

“We put a bald piece underneath the wig so, when she moves, you can see skin underneath, and the hair flicking out,” said Cate Hall. “Emma was so confident [in the wig] that there was never any reticence to do any of the moves. She didn’t have to think about the wig, ever.”

Although costume designer Amy Roberts ensured that the looks always matched the setting, the softness of her ballet outfit is noticeably at odds with the imposing room. “It’s the only time where the costume and the environment didn’t go together, and deliberately didn’t go together, so she could carry on being a fish out of water,” explained Childs.

The metaphors in the set have underpinned The Crown, especially with the cold formality of Buckingham Palace. Childs revealed that, ahead of the first series, he went undercover as a tourist to tour the palace. He then recreated “the house” using a combination of 11 stately homes and four sets in Elstree Studios.

Look carefully and staircases tell their own story. When Diana leaves her flat for the palace, she leaves her friends behind and descends a staircase with blood-red walls. “Then, Ben had the brilliant idea of providing a counterpoint [by] doing a much grander version of it once she gets to the palace,” said Childs.

There, the apartment in which Diana is kept speaks of the “cold hospitality” provided by the royals. “I have a theory that they only dusted the apartment the week before she got there and, in the past, they kept it there for brides-to-be. That was my brief to myself and the set decorator.”

Diana’s appearance acts as a visual device, too. Said Hall: “We had to plot the journey strategically over 10 individual films, and Fairytale is a springboard into that journey. She’s full of hope, but we know it can’t end well. We almost had to tell the whole story in one episode.”

To begin with, “we went as minimal as possible. We kept everything soft, creamy, really round, to give her that adolescent vibe. Then, we used beauty make-up to age her though the series. So we used those nice 1980s trends with cool, glittery tones. We used angular blusher, blue eyeliner – all that stuff. That helped to underpin the emotional narrative, and also to give us somewhere to go to tell that whole story.”

But blue eyeliners presented a particular challenge. Because their colours change with different lenses and cameras, the crew needed to camera-test them all. “We turned up with a make-up shop’s worth of make-up and looked at every different blue on camera, because we had to save our punchiest blues for the end of her story,” said Hall.

Diana’s hairstyle has its own journey: three wigs were used over this series. “They’re all essentially the same haircut – it’s that unique Diana cut. But, as she moves through the series, the hair gets more processed and styled, with more highlights. By the end, it’s a real do.”

Diana’s fateful storyline will continue in the fifth series. As has become customary after two series, it is all change for the cast. Imelda Staunton takes over from Olivia Colman as Queen Elizabeth; Lesley Manville plays Princess Margaret, instead of Helena Bonham Carter, and Elizabeth Debicki (The Great Gatsby and Widows) will take the baton from Corrin to play Diana.

Both Hall and Childs are working on the upcoming series but, unsurprisingly, are tight-lipped about what’s to come. “I have this pile of scripts with my name watermarked on them, so I can’t divulge a thing. They’re juicy, aren’t they, Cate?” teased Childs.

We wouldn’t expect anything less.

Report by Shilpa Ganatra. ‘Deconstructing the Fairytale’ was an RTS event held on 24 March, chaired by presenter Anita Rani.