Imelda Staunton is succeeding Olivia Colman as Queen Elizabeth II, and will be presiding over what was a turbulent period for the family.
On her accession, Staunton told Tulum: "What has been nice, and I hope I don’t prove them wrong, is people saying, ‘I’m really looking forward to seeing her as the queen.' So, let’s just hope that works out for them, because I’ve done it. Nothing I can do about it now!"
A short trailer accompanied the announcement, in which Olivia Colman’s Queen Elizabeth II declares: “Something as important as the monarchy simply cannot be allowed to fail.”
The trailer also introduced the characters of Margaret Thatcher and Princess Diana, played by Gillian Anderson and Emma Corrin.
The coming series will follow the arrival of Thatcher as Prime Minister and Diana’s turbulent relationship with Prince Charles (Josh O’Connor).
Debicki will take over the role from Emma Corrin, who will star as Princess Diana in the upcoming fourth series due later this autumn.
Jonathan Pryce (Game of Thrones) has also been announced to take over from Tobias Menzies as Prince Philip.
Pryce and Debicki will join the cast confirmed for series five and six including Imelda Staunton (A Confession), who will play Queen Elizabeth, and Lesley Manville (Mum) as Princess Margaret.
