'The Crown': Charles' stoop comes from having 'weight of the world on his shoulders' (exclusive)

Watch: The Crown’s Josh O’Connor shares the physical challenge of playing Prince Charles

The fourth season of Peter Morgan’s royal drama The Crown lands on Netflix this November with God’s Own Country star Josh O’Connor returning as Prince Charles.

The 30-year-old actor portrays the future King from his time at university in the 1960s right up to his marriage to Diana Spencer in 1981, but he says it’s a much more physically demanding role than you might expect.

“There are definitely days when I get back and click back into place,” the actor tells Yahoo in our video above, citing Charles’ famously stooped posture as the cause of his discomfort.

“The strange thing actually, coming out of series three... between series three and series four, [was] I guess re-finding his physicality. During the series, you go down to the shops and you find yourself stooping. My partner has to remind me to stand up straight.”

Read more: Emma Corrin explains why Diana's bulimia has to be portrayed honestly

“But when it finishes it’s quite strange to then get back into it, but I find the physicality of characters is generally, incredibly helpful.

“The stoop, yes, it’s kind of referencing maybe something about his posture in real life, but actually the stooped over posture came through a decision to follow on from Prince Phillip and what Matt [Smith] was doing in series one and two, and what Tobias [Menzies] was doing in series three.

“And also that feeling of a young man with the weight of the world on his shoulders, bringing him down.”

The new season of The Crown opens with Margaret Thatcher being elected as Prime Minister in 1979, with Charles entering his 30s as an unmarried bachelor, despite having fallen in love with Camilla in season three.

The show will follow the courtship of Diana Spencer following the funeral of his uncle Lord Mountbatten, and will follow their relationship right up and including their wedding in 1981. With the power of hindsight, we know their marriage is doomed, but the show promises to show it began with a genuine and often sweet romance between the two.

“What was really important is that we didn't signpost any kind of failings in the marriage,” O’Connor said at a press conference for the show. “When they start this marriage, yes, there were the kind of issues of maybe it being manipulated, and pushed through very quickly.”

“Hopefully what we might like been able to capture is their really organic connection,” adds Emma Corrin, who plays a young Diana. “It's like that excitement, that rush you get of meeting someone that you think, ‘wow’, there's like something here that you can't quite describe.”

The fourth season of The Crown launches on Netflix on 15 November.

Watch: A teaser for The Crown S4