Speaking about portraying one of the most prominent members of the royal family, O'Connor reveals that although he wasn't familiar with the Windsor history at the beginning, he has come to learn more about the monarchy since appearing on The Crown.
"There is so much I didn't know and it's actually weird because with The Crown, the research has been really helpful.
"Ultimately, everyone can go on to YouTube and find any interview with Prince Charles from that period.
"But what is interesting about The Crown and why I think it touches audiences is that [writer] Peter Morgan doesn't just present us with what we can see on YouTube.
"He goes behind closed doors and shows the conversations."
Josh continues: "There is a lot about Prince Charles talking about the environment, which is brilliant, but I can imagine behind closed doors that him and Camilla aren't talking about the environment all the time."