Wills, Kate attend 'African Cats' London premiere The Duke and Duchess of Cambridge, center, arrive under an umbrella for the UK P...

Wills, Kate attend 'African Cats' London premiere

The Duke and Duchess of Cambridge, center, arrive under an umbrella for the UK Premiere of 'African Cats', in aid of 'Tusk Trust', at the BFI Southbank in central London, Wednesday, April 25, 2012. (AP Photo/Joel Ryan)

The Duchess of Cambridge attends the UK Premiere of 'African Cats' at BFI Southbank Wednesday April 25, 2012 in London, England. (AP Photo/Chris Jackson, Pool)

The Duke and Duchess of Cambridge arrive under an umbrella for the UK Premiere of 'African Cats', in aid of 'Tusk Trust', at the BFI Southbank in central London, Wednesday, April 25, 2012. (AP Photo/Joel Ryan)

Prince William and his wife Kate were guests of honor at the U.K. premiere of Disneynature's "African Cats" on Wednesday.

Filmed in Kenya's Masai Mara region from August 2008 to October 2010, "African Cats" follows a pride of lions and a family of cheetahs in the savanna. British actor Sir Patrick Stewart narrates the documentary, which is directed by Keith Scholey ("Big Cat Diary") and Alastair Fothergill ("Earth," ''Deep Blue").

The event was held at the British Film Institute on London's Southbank, and served as a charity fundraiser for the conservation group Tusk Trust.

Tusk Trust has 40 projects in 17 African countries that aim to protect wildlife, alleviate poverty and encourage education in rural communities. Prince William has been the charity's Royal Patron since 2005.

"It's what we call an 'integrated approach' to conservation," said Charlie Mayhew, the charity's chief executive. "It's really that integration that has drawn Prince William as our patron. It's something that he believes passionately in, and tonight's premiere of 'African Cats' just gives us an opportunity to communicate that onto the global stage."

Scholey and Fothergill said keeping track of the stars in "African Cats" was a substantial task.

"The most challenging (part) was actually to stay with our cats for a whole two year period," Scholey said. "These are wild animals, they can go wherever they want, and we had to stay with the same characters, so that was quite hard."

"We're looking here at a drama, a soap-opera, but it's all real-life," said cameraman Simon King. "There are elements of the story that we couldn't possibly have hoped to have written. The natural world wrote the script."

"African Cats" will be released in the U.K. and Ireland on Friday.

(Agencies)