Helena Bonham Carter is Officially Joining The Crown Season 3

We now know to be true what's long been rumored: Helena Bonham Carter has officially been cast as Princess Margaret in season 3 of The Crown.

"I'm not sure which I'm more terrified about -- doing justice to the real Princess Margaret or following in the shoes of Vanessa Kirby's Princess Margaret," said Bonham Carter in a statement. "The only thing I can guarantee is that I'll be shorter (than Vanessa)."

Related | Claire Foy Was Paid Less Than Her Male Co-Star for The Crown

BAFTA and Royal Television Society-winning actor Jason Watkins will also join the season 3 cast, as Prime Minister Harold Wilson, who governed the United Kingdom from 1964-1970 and once more from 1974-1976.

Olivia Colman, who won a Golden Globe for her role in The Night Manager, will take on the role of Queen Elizabeth II, replacing Claire Foy as the series picks up in the time frame of 1964-1976. Prince Philip, meanwhile, will now be played by Tobias Menzies, who earned a Golden Globe nom for Outlander.

Season 3 will not air until 2019.