The actors chosen to play the Duke and Duchess of Cambridge when they appear in The Crown have said they feel "honoured" by the opportunity.
According to Deadline, two actors will play Prince William - Rufus Kampa in his younger days and Ed McVey in his late teens and early 20s.
Kate will be played by Meg Bellamy, the website reported on Friday.
Reacting to the announcement, Bellamy posted on Instagram: "Oh boy - it's official!
"So beyond excited! Cannot wait to join this wonderful project and so honoured to be working alongside such a talented cast."
Tagging her co-star, she added: "@ed_mcvey_ let's do thisss!"
McVey thanked Variety magazine for reporting on the news on his Instagram.
The London Theatre where he currently works as part of the front of house team, the Kit Kat Club, also posted their congratulations.
"Sensational news that Ed McVey, a member of our epic front of house team, just got announced as Prince William in the new series of The Crown. We're so proud of you," they wrote.
McVey replied: "This has made my heart incredibly full.
"Such amazing people and such an amazing show."
Kampa, who Deadline claims will portray William as he copes with the death of his mother Diana, is yet to break his silence.
All three actors have never starred on the small screen before and will make their TV debuts in season six of The Crown, which will be shot this year.
Prince Harry yet to be cast for season six
Season five, which stars Imelda Staunton as the Queen, Elizabeth Debicki as Princess Diana, and Dominic West as Prince Charles, is expected to air on Netflix in November.
West's own son, Senan West, portrays William in the final episode of season five, with Timothee Sambor also playing the young prince.
Actors Teddy Hawley and Will Powell will both play a young Prince Harry, but his part is yet to be cast for season six.
McVey graduated from Drama Centre London last year and has been an understudy in the play Camp Siegfried at the Old Vic.
His plot lines will include William's courtship of the now-Duchess of Cambridge, including how they met at the University of St Andrews in Scotland in 2001.
She will be depicted by Bellamy, who is a TV newcomer, having been involved in amateur dramatics and film-making.
She and Kampa were auditioned after sending self-taped videos following a casting call on social media.
Kampa has extensive experience on the stage after making his debut on the West End three years ago, playing roles in Sue Townsend's The Secret Diary of Adrian Mole 13 3/4s: The Musical and has performed in productions off-West End.