Helena Bonham Carter is set to play Princess Margaret in the next two seasons of 'The Crown'.

Helena Bonham Carter

Helena Bonham Carter

The 51-year-old actress is reportedly "all but confirmed" to play the riskier royal - the sister of Queen Elizabeth - in the HBC series after the decision was made to recast Vanessa Kirby, who played the part in the first two seasons, in order to continue the story, according to the Evening Standard newspaper.

The award-winning star was being eyed up to play Elizabeth in the show following the departure of Claire Foy but bosses decided she'd be better suited to Margaret while Olivia Colman will play the matriarch.

The 43-year-old star will play the role for the next two series - documenting the fourth decade of Elizabeth's life - and then producers will go on the hunt for another actress to take over the reins in order to document the queen's life from her 60s to her 90s - providing Netflix decide to recommission it.

The first instalment proved a huge hit with viewers - with Claire winning a Golden Globe for her portrait of Elizabeth II in the first ten episodes - and the second was equally as successful this year.

Although fans are no doubt devastated to see the 33-year-old beauty leave, it has always been clear from the start that another actress would be contracted to play Her Majesty from her 40s through to her 60s.

Speaking recently, Claire said: "This is the last stint, it's over, I'm done.

"I always knew it was only going to be two series and then part would be reincarnated and someone else takes over. That's the nature of the part."

But Claire isn't the only one leaving the cast, as Matt Smith - who played Prince Philip - is also being replaced with an older actor for the next chapter.

It's not yet known who has been chosen to play the queen's spouse.