Emma Watson, Kate Moss and Cara Delevingne glide into Windsor Castle for star-studded event
Actress Emma Watson, 'Sherlock' star Benedict Cumberbatch, and Hollywood actresses Cate Blanchett and Helena Bonham Carter were guests at Windsor Castle tonight.
Prince William has been joined by a host of stars from screen and fashion to a leading cancer-specialist hospital.
Supermodels Kate Moss and Cara Delevingne were also invited to the black-tie do.
Designer Ralph Lauren was also present since he has made a generous donation to help fund a new breast cancer research centre which has been named in his honour.
The fashion guru dressed many of the stars attending the dinner hosted by William.
The Royal Marsden was founded as the Free Cancer Hospital in 1851 by Dr William Marsden, and was the first hospital in the world dedicated to cancer treatment and research into the causes of cancer.
Bonham Carter said events like the dinner were needed to raise awareness and funds for the fight against cancer.
She said: "It requires a huge amount of money to come up with a cure for cancer
"We now live in times when it doesn't mean death, a lot of people are living with the disease. It's very different from when I was a child, the C word was taboo. Hopefully, for my children, it will be a thing of the past."
She chatted for a few minutes with the Duke as he met guests and joked afterwards about how they had met on the island of Mustique and she tried to persuade him to become godfather to her daughter.
The Duke became its president in 2007. His mother Diana, Princess of Wales held the same position from 1989 until her death in 1997.
Stars from popular period drama Downton Abbey - Laura Carmichael and Allen Leech - were among the guests, as was Game of Thrones actress Sophie Turner.
Cumberbatch described how he had an affinity with the Duke, with the two men being similar ages, and described him as a "stand up" guy.
He added after speaking to William: "I'm here tonight to show my support, I've done work for various cancer trusts and charities but for the Marsden, it's the first thing I've done for them.
"I've sadly known a lot of people who have been through their doors but the other extent they've been incredibly well treated."
The actor went on to praise the financial support the Royal Marsden has received from Ralph Lauren.
The evening's entertainment was a performance by award-winning singer-songwriter Emeli Sande.