Netflix's hit royal drama series regularly recasts its main characters as the story moves through time and The Affair star West is due to take over the role of Charles from Josh O'Conner in series five.
After a nationwide search for his son William, Variety has reported that bosses have settled on the perfect casting of Senan West, 13, a newcomer to acting and The Wire actor's real-life son.
His mother, Princess Diana, will be played by Tenet star Elizabeth Debicki, who takes over from Emma Corrin.
Senan isn't the first of West's children to appear alongside him on screen as his daughter Martha was also cast in his recent BBC series The Pursuit of Love.
The Crown's series five picks up the Royal Family's story in the 90s and is expected to introduce Senan as Prince William in the final few episodes, where he will depict an early teenage version of his character.
Prince William was 15 when his mother was killed in a Paris car crash and while it hasn't been confirmed whether the crash will be included as a scene in the series, it seems likely that the events leading up to and afterwards will.
The Kite Runner's Khalid Abdalla has also been cast as Dodi Al Fayed, who Princess Diana was in a relationship with and who also died in the 1997 crash.
Other cast changes for series five include Imelda Staunton taking over from Olivia Colman as Queen Elizabeth II, Jonathan Pryce as Charles’ father, the Duke of Edinburgh, Lesley Manville as Princess Margaret, and Jonny Lee Miller will join the series as prime minister John Major.
Claire Foy and Matt Smith originally starred as the Queen and Prince Philip in their younger days, while Margaret has previously been played by Vanessa Kirby and Helena Bonham Carter.
The Crown series 4 is currently streaming on Netflix.
Watch: Crown producers wanted to film at Princess Diana's childhood home