As per their standard practice of bringing in different actors as the characters age, “The Crown” has cast Dominic West as Prince Charles and Elizabeth Debicki as Princess Diana in Season 5.
The pair play the estranged couple through the early 1990s and take over from Josh O’Connor and Emma Corrin, who played young Prince Charles and Princess Diana during Season 4.
That season ended with the marital troubles between the two as Princess Diana discovered her husband was having an affair with Camilla Parker Bowles (played by Emerald Fennell).
Season 5 is currently under production.
source: cnn.com