The actor says he informed the Prince's Trust that he was taking on the role but didn't ask the family for any advice.
At the world premiere for season 5 of The Crown, Dominic West spoke with ET about transforming into King Charles III, who was still a prince during the 1990s when the new episodes of creator Peter Morgan's historical drama about the royal family takes place. The 53-year-old actor also opened up about why he didn't reach out to his real-life friend, Prince Harry, for any advice about his performance.
"I didn't think it was appropriate to call him up and ask him for tips," West said with a chuckle while walking the red carpet at Theatre Royal Drury Lane in London, England.
In fact, despite being friendly with the royal, the actor admitted the two haven't spoken in a while. "I haven't spoken to him for many years," West continued, explaining the two got to know each other in 2013, when they both participated in the Walk With the Wounded charity race through Antarctica. "We did walk to the South Pole together with a lot of wounded soldiers, so I got to know him pretty well."
While West didn't turn to Harry for any tips, he did think it was prudent to let Harry's father know that he had joined the Emmy-winning Netflix drama, taking over the role of Prince Charles from Josh O'Connor, who portrayed him in seasons 3 and 4.
"I just thought I would inform the Prince's Trust that I was playing the part. And I felt they had a right to know that. So, that's as far as it went," the actor said, referring to the charitable organization founded by Charles in 1976 before revealing that he did not have to resign from any position despite reports he offered to quit as ambassador.
"You can't really resign. It's not really a job," he clarified.
That said, royal expert Katie Nicholl told ET that West's portrayal might prove uncomfortable for Harry. "For Dominic West, going into that role playing Charles, during some of the most tumultuous years of the royal family -- and at a time when Charles' popularity was absolutely rock bottom -- I think any actor would jump at the chance because, obviously, it's a wonderful opportunity," Nicholl said.
"But [they might] also think twice about it as well. I mean, when they were making The Crown, they would have known, given the queen's age, given her frailty, [that] there was always a real risk that this series was going to go out when she was either close to death or indeed had died, as is the case," she continued.
While there may be some lingering awkwardness around taking on the coveted role, which previously earned O'Connor an Emmy for Outstanding Lead Actor in a Drama Series, West admitted that his first camera test with co-star Elizabeth Debicki, who joins seasons 5 and 6 as Princess Diana, was quite scary.
"I remember the camera test and it was me and Elizabeth. We're doing a test together and she immediately -- it felt like it anyway -- it felt like she had everything in place already and we were a couple of months off starting and I felt I hadn't got anything," West recalled about feeling unprepared at the time after first getting into full costume as Charles.
"Also, of course, you feel in front of a crew that's been doing this for five years with two other casts and you think everyone's going, 'Dear,'" he continued, with a laugh. "So, it was pretty frightening."
Although season 5, which has garnered a certain amount of controversy leading up to its premiere on Nov. 9, covers a scandalous time for the royal family, including Charles and Diana's divorce and his leaked phone call with Camilla Parker Bowles, West feels that the series is still a love letter to Queen Elizabeth II.
"I think a lot of [Peter Morgan's] career has been a love letter to the queen," the actor shared. "I think, definitely, I think there's no question that [everything] he writes and we all act out of immense admiration and respect for her."