Nelson Mandela dead: Barack Obama, David Cameron and Enda Kenny lead tributes to South Africa's first black president
US President Barack Obama, Prime Minister David Cameron and Ireland's Taoiseach Enda Kenny have led tributes to South Africa's first black president Nelson Mandela, who has died aged 95.
Mr Cameron said "a great light has gone out in the world".
The flag at No 10 will be flown at half-mast in honour of the former leader, who was a "hero of our time", the Prime Minister said.
Taking to Twitter, he wrote: "A great light has gone out in the world. Nelson Mandela was a hero of our time. I've asked for the flag at No10 to be flown at half mast."
US president Barack Obama said the world has lost an influential, courageous and "profoundly good" man.
Mr Obama said Mandela "no longer belongs to us. He belongs to the ages."
Speaking from the White House, Mr Obama said he was one of the countless millions around the world who was influenced by Mandela.
He met Mr Mandela's family earlier this year when he visited South Africa. But he did not meet the ailing leader, who was in hospital throughout his visit.
Irish Taoiseach Enda Kenny described Mr Mandela's death as "a great light extinguished".
"The name Mandela stirred our conscience and our hearts. It became synonymous with the pursuit of dignity and freedom across the globe," Mr Kenny said.
The Taoiseach said Mr Mandela changed life in South Africa, and humanity.
"As we mark his passing, we give thanks for the gift of Nelson Mandela. We ask that his spirit continues to inspire, guide and enlighten us as we strive to bring freedom and dignity to the family of man, our brothers and sisters, across the world," he said.
"I offer my deepest sympathies, on behalf of the Irish Government and people, to his family, to his friends and supporters, and to the Government and the people of South Africa."
Former US president Bill Clinton said: "Today the world has lost one of its most important leaders and one of its finest human beings. And Hillary, Chelsea and I have lost a true friend.
"History will remember Nelson Mandela as a champion for human dignity and freedom, for peace and reconciliation.
"We will remember him as a man of uncommon grace and compassion, for whom abandoning bitterness and embracing adversaries was not just a political strategy but a way of life.
"Our thoughts and prayers go out to Graca and his family and to the people of South Africa.
"All of us are living in a better world because of the life that Madiba lived.
"He proved that there is freedom in forgiving, that a big heart is better than a closed mind, and that life's real victories must be shared."
American civil rights leader Jesse Jackson said Mr Mandela's "imprint" would be "everlasting".
"My heart weighs heavy," said Mr Jackson, who has been in the UK this week and spoke to students in Cambridge on Monday. "The imprint he left on our world is everlasting."
UK Shadow Chancellor Ed Balls wrote: "Seeing Nelson Mandela walking free is one of the great moments of my life - proving leadership and hope can triumph. Thank-you. RIP"
Baroness (Betty) Boothroyd, the former Commons speaker, fondly recalled the memories about a visit President Mandela made in 1996.
She said: "I welcomed many leaders to Westminster when I was Speaker but he was by far the most remarkable.
"His speech to the joint Houses of Parliament in Westminster Hall in 1996 was a masterpiece of reconciliation after the bitter years of apartheid. He represented 'an outstanding victory of the human spirit over evil', I told him.
"He wrote to me afterwards of his delight at the pomp and ceremony of the occasion and its 'majesty and dignity'.
"He was especially touched by the Queen's graciousness towards him and the warmth of the British people.
"He was kind enough to add 'It is friends like yourself who have contributed to making our country the democratic rainbow nation we are today'.
"His modesty during that visit was extraordinary and people loved him all the more because of it. One anecdote illustrates his foresight. On his arrival at the entrance to the Commons, I cautioned him about the treacherous steps in Westminster Hall and said we would take them at his pace.
"'Don't worry', he replied. 'I came to look at them at six o'clock this morning'. With that, the trumpets sounded, he took my hand and we entered together without mishap. He had foreseen the difficulty and worked out the solution hours before.
"He was still looking forward when we last met in South Africa when I went there as Chancellor of the Open University. he said that when he finally entered the pearly gates he would join the local branch of the African National Congress."
Former prime minister Tony Blair said the political leader was a "great man" who had made racism "not just immoral but stupid".
"He was a unique political figure at a unique moment in history," he said.
"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.
"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.
"I worked with him closely, and remember well his visits to Downing Street. He was a wonderful man to be around, with a sharp wit, extraordinary political savvy and a lovely way of charming everyone in a building.
"He would delight in making sure that the person on the door or serving the tea would feel at home with him and be greeted by him with the same kindness and respect he would show a leader. So the warmth of his personality was equal to the magnitude of his contribution to the world.
"He was a great man, a great leader and the world's most powerful symbol of reconciliation, hope and progress."
Belfast Telegraph Digital