Prince William and his wife, Kate, were attending the London film premiere of "Mandela: Long Walk to Freedom" when the news broke.
"We were just reminded of what an extraordinary and inspiring man Nelson Mandela was and my thoughts and prayers are with him and his family right now," William said upon exiting the film.
Former UK Prime Minister Tony Blair praised Nelson Mandela as a "unique political figure at a unique moment" in history.
"Through his leadership, he guided the world into a new era of politics in which black and white, developing and developed, north and south, despite all the huge differences in wealth and opportunity, stood for the first time together on equal terms," Blair said.
"Through his dignity, grace and the quality of his forgiveness, he made racism everywhere not just immoral but stupid; something not only to be disagreed with, but to be despised. In its place he put the inalienable right of all humankind to be free and to be equal."
In Haiti, a Caribbean nation that became the world's first black republic in 1804 through a successful slave revolt, Mandela symbolized the struggle for black equality.
"Mandela is not only the father of democracy in South Africa, but is also a symbol of democracy," said Haitian President Michel Martelly. "And like any symbol, he is not dead. He is present in all of us and guides us by his lifestyle, his courage and faith in the true struggle for equality."
