Last night lucky Prince William rubbed shoulders with A-listers such as Cara Delevingne, Kate Moss and Benedict Cumberbatch. The stars were among 200 guests invited to a glamorous charity event held at Windsor Castle, in aid of celebrating the work at The Royal Marsden Cancer Hospital.
Many of the guests - including actress Cate Blanchett - were wearing Ralph Lauren in tribute to the announcement that the designer will be funding a new breast cancer centre at the hospital.
Take a look at our gallery to see who else attended and who wore what.
The model looked stunning in a sheer black gown.
Jamie Hince and Kate Moss
Accompanied by her musician husband Jamie Hince.
The actress wore an asymmetrical ivory silk dress from Ralph Lauren.
The model wowed in a sparkling black halter-neck.
Cara Delevingne and Mario Testino
Accompanied by the famous photographer.
The 'Harry Potter star wore a silk skirt and shirt both Ralph Lauren Collection.
The actor wore looked handsome as ever in a classic Ralph Lauren suit.
The Downton Abbey Actress wore a flattering feathered gown.
Helena Bonham Carter
The actress wore a midnight silk and taffeta dress from Ralph Lauren Collection.
Ralph Lauren and Ricky Lauren
The designer was the talk of the evening thanks to his substantial donation to the cause.
The Game of Thrones Actress in a full length black gown.
The actress looked gorgeous in this slinky backless satin gown.
Editor - in - chief at British Vogue.
The actress looked chic in this simple but sumptuous grey number.
Jenson Button's model girlfriend stood out in a strapless red dress.
Lily James, Cate Blanchett and Kate Moss
Inside the two Kates got cosy with Lily James.
Cara Delevingne and Kate Moss
The models showed us just how to work the LBD - The Long Black Dress.
Prince William and Kate Moss
The model enjoyed deep conversation with the Prince.
Prince William and Emeli Sande
The Prince greeting one of music's emerging stars.
Ralph Lauren, Cara Delevingne and Ricky Lauren
The model showed her appreciation for the man of the night.