He said: "We are delighted that Their Royal Highness's the Duke and Duchess of Cambridge are here for this very special evening.
"We're particularly pleased that the Duchess is here because she will be such a support to her husband.
"After watching a recent episode of Who Do You Think You Are? he is still recovering from the devastating news he is related to Danny Dyer."
The Duke and Duchess of Cambridge laughed at Stephen Fry's joke at the 2017 BAFTAs
Stephen made a joke that Prince William was "devastated" to learn he was related to Danny Dyer
BAFTAs 2017: Best and worst dressed
Sun, February 12, 2017
BAFTAs 2017: The best and worst dressed from star-studded red carpet at the Royal Albert Hall.
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BAFTAs 2017 in pictures
The devastating news he is related to Danny Dyer
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EastEnders actor Danny was left speechless during the ancestry programme when he was informed he was a descendant of Edward III.
Luckily for the comedian, Kate and Wills were amused and laughed politely at the joke.
The Duchess stole the show on the red carpet earlier on in the evening dressed in a breathtaking black floral gown.
Danny Dyer discovered he was a direct descendant of Edward III on Who Do You Think You Are?
BAFTAs2017: The Duchess stunned in a floor-length Alexander McQueen gown
With her husband by her side, the 35-year-old wowed in the Alexander McQueen gown, costing £2880.
The Royal couple joined A-list celebrities at the star-studded event, which saw William present the Fellowship Award on stage to Mel Brooks.