Dominic West reached out to King Charles after he was cast in 'The Crown'.
The 53-year-old actor plays Charles in the hit Netflix series, and he's revealed that he contacted The Prince's Trust - the charity founded by Charles in 1976 - after he landed the role.
Dominic said: "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."
By contrast, Dominic didn't reach out to Prince Harry about his part in the show.
The actor actually got to know Harry in 2013, when they both participated in the Walk With the Wounded charity race through Antarctica.
He told 'Entertainment Tonight': "I didn't think it was appropriate to call him up and ask him for tips."
Dominic feels as though he knows Harry, 38, "pretty well" - but they haven't actually spoken to each other in years.
The actor shared: "We did walk to the South Pole together with a lot of wounded soldiers, so I got to know him pretty well."
The new series of 'The Crown' is the first since the death of Queen Elizabeth, and Peter Morgan - the show's creator - recently paid a glowing tribute to Britain's longest-reigning monarch.
Peter, 59, described the hit show as a "love letter" to the queen.
He said: "'The Crown' is a love letter to [the queen] and I've nothing to add for now, just silence and respect. I expect we will stop filming out of respect too."
It was subsequently confirmed that production work on season six of the show had stopped out of the respect for the late monarch.