The Duke of Cambridge will dine with a host of Hollywood stars and leading faces from the fashion world tonight when he hosts a dinner in celebration of one of the world's leading cancer-specialist hospitals.
William will preside over a black-tie event at Windsor Castle in honour of the Royal Marsden, and is expected to be joined by Sherlock star Benedict Cumberbatch, actress Helena Bonham-Carter and supermodels Kate Moss and Cara Delevingne.
Designer Ralph Lauren, who has made a generous donation in aid of the hospital, will also be among the guests.
Cumberbatch, Bonham-Carter and the celebrity photographer Mario Testino are the guests of Alexandra Shulman, editor of the fashion magazine Vogue and a trustee of the Royal Marsden Cancer Charity - which raises funds for the medical institution.
It 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.
The Duke became its president in 2007, following in the footsteps of his mother Diana, Princess of Wales who held the same position from 1989 until her death in 1997.
William has had a long association with the hospital, spending two days work experience at the institution's children's unit in December 2005.
He helped out in various departments, including medical research, catering and fund-raising, and toured a number of the wards.
Last November he visited the Royal Marsden in Chelsea, west London, where he viewed sections of a breast reconstruction procedure and the removal of a bladder tumour involving two patients.
At the end of the night the guests will be entertained by a performance from award winning British singer songwriter, Emeli Sande.