The Durrells star Josh O'Connor has been cast as Prince Charles in the next instalment of The Crown.
The actor, who also starred in God's Own Country, said he was "thrilled to be joining The Firm".
Olivia Colman as the Queen and Helena Bonham Carter as Princess Margaret have also been announced.
Marion Bailey, who played the Queen in the play Handbagged, will play the Queen Mother and Erin Doherty will play Princess Anne.
O'Connor will play the role of Prince Charles in seasons three and four, which the actor says will "follow some of the most turbulent events in the Prince of Wales's life and our national story. I'm excited to be bringing to life the man in the midst of it all.
"I'm very aware it's a formidably talented family to be joining, but reliably informed I have the ears for the part and will fit right in."
Bailey, who appeared in the Oscar-nominated film Allied, said it was "wonderful" to be joining the Netflix series.
"It's a brilliant show and we have a tough act to follow, but what a gift to be playing the fascinating and greatly loved Queen Mother. Thrilled to be on board and working with such a top-notch team."
Doherty, who has appeared in Call the Midwife, said it felt "ridiculously special and surreal" to join the show.
The Crown Season three will launch on Netflix in 2019.