The Duke and Duchess of Cambridge walked the red carpet tonight as they highlighted Africa's threatened wildlife at the UK premiere of a big-cats film.
The screening of the nature documentary raised funds for The Duke's UK-based animal conservation charity Tusk Trust.
Mark Knopfler, lead singer of the group Dire Straits, was among the guests along with filmmaker Guy Ritchie and Dragons' Den judge Deborah Meaden, a patron of Tusk Trust.
The wildlife film tells the story of life on Kenya's plains for a pride of lions and a family of cheetahs as they battle for survival.
Hollywood star Patrick Stewart narrates the true-life story of cheetah Sita bringing up her five cubs in the Masai Mara game reserve and of Mara, a six month-old lion cub being raised by her mother Layla.
The Duke is a self-confessed lover of Africa, its people and wildlife, and has worries about the current animal welfare crisis that has seen renewed interest from poachers in elephant ivory and rhino horns.
Demand from consumers in the Far East and China has seen prices for the animal products rise significantly in recent years.
During the event, The Duke made a speech, during which he said: "Films like African Cats remind us of the dramatic beauty, and the harshness, of the natural world â€“ and there is nowhere more awe-inspiring or beautiful than the vast plains of Kenyaâ€™s Maasai Mara.
"Africaâ€™s natural heritage is the worldâ€™s natural heritage. We have to preserve places like thisâ€¦not just for us, but for future generations."
Charlie Mayhew, co-founder of Tusk Trust of which The Duke is Royal Patron, said about The Duke: "He's passionate about Africa and ... he's very concerned about the current crisis.
"We are now seeing daily reports of elephants being poached across the continent and in South Africa, the country has lost 170 rhinos already this year."
He added that the number of cheetahs on the continent stands at around 10,000 to 12,000, while estimates suggest only 25,000 lions are left in Africa.
Mr Mayhew described The Duke's ability to get the wildlife message across to the public as vital for his charity's work and the efforts of others.
He said: "It's enormously important and enormously valuable to have as our royal patron Prince William. His role, despite the Tusk agenda, on the global stage (is important) not just for our work but communicating the conservation message that everybody in conservation wants to get across. He's a powerful advocate for conservation in general."
He added: "Kate as we know got engaged to Prince William out in Africa and she's got the same general love of the continent as he has. She very kindly came to LA (with The Duke) to launch our USA patrons circle. I cannot tell you how successful that was."
The Duke and Duchess also met children and young adults from charities that have Their Royal Highnesses as patrons.
Princess Briggs, a former homeless teenager now a resident at a south London centre run by Centrepoint, which has The Duke as its Royal patron, said after chatting to the special guests: "It's a great opportunity I'm speechless. Kate is a role model, she's real class."
The 18-year-old, who arrived in the UK from Sierra Leone four years ago, said about The Duke: "He was talking to me about Centrepoint and how I'm doing there. I was trying to explain to him I have a lot of facilities. I have my own room. I have mentors. I feel safe and I feel comfortable."
The Duke and Duchess both spoke to Emmie Smith, nine, of Chobham, Surrey, a patient of the Royal Marsden hospital who has been in remission since February after two years and three months of treatment for leukaemia.
"She told me I looked very pretty," said Emmie.
Her mother Marie, 43, said: "The Royal Marsden rang us about 10 days ago and asked if Emmie would like to come along as a guest of William and Kate. I couldn't tell her [at first], just to make sure it was going to happen. When I told her, she jumped up and down with glee. Everyone knows we were coming here tonight."
Find out more about The Duke and Duchess of Cambridge's charities