“It is a melodrama within a family,” says Josh O’Connor, who is returning for his second season as Prince Charles in the royal family drama The Crown.

“It is not too dissimilar to The Sopranos or Succession in that sense. It’s a huge dynasty and it’s about the politics within families.”

Comparisons to some of the greatest TV dramas of modern times feel appropriate for The Crown’s fourth season, as the show reaches the most dramatic decade yet for Queen Elizabeth II and her family.

Charles and Diana, Camilla, Thatcher, the Falklands, the death of Lord Mountbatten - the show struggles to contain all the key moments to just the 10 episodes.

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The increase in shocking events is matched by the show’s brighter colours and increase in pace for what writer and creator Peter Morgan describes as the first “modern season” of The Crown.

“I think the first couple of seasons had an almost Edwardian hangover. With all their waxed moustaches, even though it was set in the early 50s, some of them had barely emerged from the 20s,” he argues.

“I was pinching myself that we were doing The Crown and playing a song by George Michael. Up to that point we had been in deep history.

“The Diana era feels more current, more vivid and alive. It’s a real joy to see.”

Bringing in Diana

Emma Corrin as Diana in The Crown Netflix

Newcomer Emma Corrin delivers an incredible performance, despite huge pressure and scrutiny, taking on the almost impossible task of playing Diana Spencer.

Morgan admits that he was daunted by writing Diana, describing her legacy as “complicated”.

“She is a polarising figure. She is always quite warmly thought of, but there is an unmistakable feeling she was as much the agent of her own downfall as she was the victim of others' cruelty,” he said.

“I feel the same way about Prince Charles. Just as you have him pegged as one thing, he turns out to be something quite different.”

Corrin heaped praise on Morgan’s writing for capturing all sides of the late princess.

“Everyone can be petulant and manipulative sometimes. And everyone can complain and not enjoy things and be sad,” she said.

“Peter just creates very well rounded characters, which is a blessing to play. Diana took me all over the place. She was an absolute gift.”

Emerald Fennell, who plays Camilla Parker-Bowles in the series, said that working on the series reframed her opinion of Diana.

“The thing that comes to mind is Charles and Diana’s Australia trip, which of course looks shiny and lovely in all the pictures and papers, but seeing the behind-the-scenes tension is just fascinating,” she said.

“It reframes everything you think you knew about these people.”

This isn’t a Spitting Image impressions show

Helena Bonham-Carter as Princess Margaret in The Crown Netflix

Although Corrin does a decent job of capturing Diana’s head tilt and Gillian Anderson delivers a very gruff Margaret Thatcher accent, all the actors in the series are at pains to stress they’re not interesting in doing perfect impressions.

Tobias Menzies, who returns as Prince Philip, said the actor's main goal was to go beyond telling a story about the royal family.

“We want people view them as people, daughters, fathers and marriages,” he said. “All these domestic, ordinary things, just within a very arcane, very unusual family situation and set of buildings.”

Erin Doherty, who returns as the scene-stealing Princess Anne, said: “The beating heart of these human beings, that’s what people are drawn to. People see the similar qualities and that is what is so magnetic about the show.

“It demystifies these iron-cast people and makes you realise, ‘Oh god, that is what I would do’.”

Olivia Colman in The Crown season 4 Netflix

Colman said “You see the strings of love between these people and everyone recognises that in their own families. No matter what the wallpaper is behind you, or how posh the bottle is you’re drinking, there is a grandmother, children, siblings, the in-laws.”

One member of the cast who found it easier getting back into character second time around was Helena Bonham Carter, who returns as Princess Margaret.

“A relief for this season was that we could just play our age,” she said. 

“Last season we were much older than what we were meant to play so we had to diet and things.”

Laughing, she adds: “This time we could just eat.”

Princess Diana's fashion story

Emma Corrin as Diana in The Crown Netflix

The costume department on The Crown is without rival when it comes to TV in 2020.

Emmy Award winner Amy Roberts faced her biggest challenge yet as the show arrives in the 1980s and in particular telling the story of Diana.

“The evening gowns, shoulder pads and power suits were very much at the later part of her life,” explains Corrin.

“The years we cover in this season, she hasn’t really found that voice with fashion as we know it now. When she was younger she didn’t really have a sense of style in a particular way.”

One of the most striking parts of Diana’s joining the show isn’t just her dancing around her flat to Blondie, but her colourful knitwear, which clashes with the formal elegances we’ve come to expect from The Crown.

“Before she enters the Palace, there are a lot of sweater vests – which are amazing,” explains Corrin.

“But when they got her in the Palace, they uniformed her. They put her in jackets and skirts and Amy Roberts, who does the costumes on the show, described it as dressing her up like a doll.

“It’s only later when she goes to New York, which is a massive turning point, where she starts to fight back and reclaim parts of herself and her personality. That’s when those amazing ball gowns and fashion moments happen.

“The shift and trajectory of her clothes in the season are very much the trajectory of her character, they show that growth.”

The hardest working team on the show

Gillian Anderson as Margaret Thatcher in The Crown season 4 Netflix

“All the different departments help in one way of another. Whether it’s the wig department, the hair or the costumes,” says Gillian Anderson, who is transformed into Britain’s first female Prime Minister for a remarkable performance.

“I didn’t quite understand how many costume changes there would be for Thatcher. But how Amy works with her team is really amazing. How they scope it and the colours they bring in. They add a spark of creativity and texture and I don’t know how they keep track.

“They built nearly all the pieces for the characters and that is such a huge undertaking. I think she probably worked more hours than pretty much anyone else in the show.”

Explaining how the work of the costume team benefits the actors, Anderson added: “Putting on that bodysuit, which increases my waistline a little bit and putting on her wig and her shoes, and the very uncomfortable stockings that she would have worn, all of those elements together help make you feel more confident.

“All the contributions from the different departments meant that I look from the outside how I felt as an actor on the inside.”

Colman admitted that she found it “spooky” sitting opposite Anderson in full hair and wardrobe and was similarly shocked when Corrin arrived on set as Diana.

Sitting opposite Gillian, it’s so like she’s there. The work that goes in is incredible. Three quarters of my job is done by hair and wardrobe. It’s spooky.

“When she has the wig on and make-up, she puts the chin down and suddenly, it’s ‘wow’. It’s like the real person has walked in the room.”

Olivia Colman campaigning for return

Olivia Colman in The Crown season 4 Netflix

When The Crown returns for season 5, it will have a very different look.

Colman, Menzies and Bonham-Carter are all bowing out and will be replaced by Imelda Staunton, Lesley Manville and Jonathan Pryce respectively for the show’s final episodes.

“I think it would be a bit rich if I tried to give Oscar-nominated Jonathan Pryce some tips,” laughs Menzies.

Meanwhile, Emerald Fennell jokes about the future Camilla: “My advice would be let the hair do the work.”

However, one star hasn’t completely given up hope that they won’t be back in Buckingham Palace for one more scene.

“Maybe there will be some sort of dream sequence Pete?” pleads Colman.

Maybe he’s being polite, but the writer doesn’t completely rule out the possibility of a comeback.

“I don’t know. I don’t want to say anything. I’m toying with a few ideas,” says the writer, cryptically.

“I’ve always wanted to work with Imelda,” adds Colman.

“I’ll see what I can do,” he replies.