Fresh Air had a superb interview with Peter Morgan the writer of the films
The Queen” and “Frost/Nixon” plus the award-winning television series “The Crown”. You can take a Net Flix 30 day  free trial run and binge watch The Crown. (20 hours are available) Fascinating stuff about how his team does research and what the royal family thinks about the series. He talks about the casting of Claire Foy as Elizabeth in “The Crown” . He is an articulate speaker that you will find engrossing.

https://en.wikipedia.org/wiki/Peter_Morgan

https://www.npr.org/2018/01/16/578281741/crown-creator-sees-britains-reigning-monarchs-as-just-a-regular-family