Leaders and politicians from around the world have paid tribute to former president Nelson Mandela following his passing at the age of 95.
America's first black president Barack Obama on Thursday mourned Nelson Mandela as a "profoundly good" man who "took history in his hands and bent the arc of the moral universe towards justice."
Obama - who met the former South African president briefly only once in 2005, but was inspired to enter politics by the anti-apartheid hero's example - paid a sombre heartfelt tribute within 45 minutes of Mandela's death being announced.
"We will not likely see the likes of Nelson Mandela again," Obama said in a televised statement, hailing his political hero for his "fierce dignity and unbending will to sacrifice his own freedom for the freedom of others."
Obama said Mandela, in his journey from a "prisoner to a president," transformed South Africa and "moved all of us."
"He achieved more than could be expected of any man."
"Today he's gone home and we've lost one of the most influential, courageous and profoundly good human beings that any of us will share time with on this Earth.
"He no longer belongs to us; he belongs to the ages."
Obama recalled how his passion for change was stirred by taking part in an anti-apartheid rally - his first ever political act.
"The day that he was released from prison gave me a sense of what human beings can do when they're guided by their hopes and not by their fears," Obama said.
Former US president Bill Clinton, who was in office when Mandela took power in South Africa, on Thursday mourned the death of a "champion for human dignity and freedom".
"Today the world has lost one of its most important leaders and one of its finest human beings," Clinton said in a statement.
"History will remember Nelson Mandela as a champion for human dignity and freedom, for peace and reconciliation," he added.
The Clinton and Mandela families became close, with the former US president visiting Mandela on the eve of his 94th birthday.
"Hillary, Chelsea and I have lost a true friend," Clinton said.
"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."
Clinton extended his thoughts and prayers to Mandela's widow Graca, his family and the people of South Africa.
"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."
Reaction from UK, Ireland
British Prime Minister David Cameron on Thursday said "a great light had gone out" following Mandela's death as flags flew at half-mast at his Downing Street Office.
"Nelson Mandela was a towering figure in our time; a legend in life and now in death - a true global hero," said Cameron.
"Across the country he loved they will be mourning a man who was the embodiment of grace," he added.
"Meeting him was one of the great honours of my life. My heart goes out to his family - and to all in South Africa and around the world whose lives were changed through his courage.
"A great light has gone out in the world."
British opposition leader Ed Miliband said the world "had lost the global hero of our age".
"Nelson Mandela showed us the true meaning of courage, hope, and reconciliation," he stressed.
"From campaigner to prisoner to president to global hero, Nelson Mandela will always be remembered for his dignity, integrity and his values of equality and justice.
"He moved the world and the world will miss him deeply."
London mayor Boris Johnson praised Mandela's power of forgiveness.
"He faced down the tyranny and oppression of apartheid by embracing unity, by rejecting division, by proving without rancour or recrimination that his way was the right way, the best way, and the only way to bring about change," he said.
"Londoners, brought up in a city where the values of diversity and equality were celebrated not suppressed, forged a unique bond with Mandela and the struggle he embodied.
"He was without doubt the pre-eminent statesman of his age. No statesman in history can match him for resilience, for grace, and for forgiveness.
"A great heart is stilled."
Former prime minister Tony Blair said Mandela had made racism "not just immoral but stupid".
"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," recalled Blair.
"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," he added.
Archbishop of Canterbury Justin Welby, head of the world's Anglicans, mourned the loss of South Africa's "greatest citizen and its father."
"Nelson Mandela, fighting to the end, is freed to be with his God in joy and reward for his great service and sacrifice.
"We pray for his family, for his friends and for his country," added the archbishop.
Irish prime minister Enda Kenny paid tribute to the "gift" of Mandela, and offered the country's deepest sympathies to the people of South Africa.
"The name Mandela stirred our conscience and our hearts. It became synonymous with the pursuit of dignity and freedom across the globe," he said in a statement.
"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 added.
Scotland First Minister Alex Salmond said the world has lost a "towering statesman and outstanding political leader."
UN commemorates Madiba
UN leader Ban Ki-moon hailed Mandela as a "giant for justice" who had also left his mark with a profound sense of human decency.
"Many around the world were influenced by his selfless struggle for human dignity, equality and freedom. He touched our lives in deeply personal ways," Ban told reporters in tribute to Mandela.
"Nelson Mandela was a giant for justice and a down-to-earth human inspiration," the UN secretary general added.
Minutes after the announcement of his death, the UN Security Council held a moment of silence in Mandela's memory.
Ban met the anti-apartheid hero in February 2009, and said he had been particularly struck by Mandela's "selflessness and deep sense of shared purpose."
Ban said that he had repeatedly praised Mandela for his work in ending South Africa's brutal system of dividing races.
Mandela was equally insistent in saying "there are hundreds and hundreds of known, unknown people, who have contributed to the ending of apartheid," Ban said of the encounter.
"I was deeply touched and moved and inspired."
Ban said that Africa and other parts of the world had endured centuries of suffering because of colonialism.
"Only because of such great men like Nelson Mandela" have people in Africa been able "to enjoy freedom and human dignity."
Ban said he was "humbled" by Mandela's acheivements.
"We have to learn from the wisdom and determination and commitment of President Mandela to make this world better for all."
"I'm deeply grateful for what he has left during his lifetime to make this world just and fair and equal," Ban said.
Rest of the world
Goodluck Jonathan, the leader of Nigeria, said "Mandela will always be remembered and honoured by all mankind as one of its greatest liberators, a wise, courageous and compassionate leader, and an icon of true democracy."
He described the former South African president "as a source of inspiration to the oppressed peoples all over the world."
Mandela's "death will create a huge vacuum that will be difficult to fill in our continent," Jonathan said.
Australian Prime Minister Tony Abbott on Friday hailed Mandela as "a truly great man".
"Nelson Mandela was one of the great figures of Africa, arguably one of the great figures of the last century," Abbott told Fairfax radio, referring to him as the father of modern South Africa.
"A truly great man."
In an official statement, the prime minister said Mandela "will forever be remembered as more than a political leader, he was a moral leader".
"He spent much of his life standing against the injustice of apartheid.
"When that fight was won, he inspired us again by his capacity to forgive and reconcile his country.
"While the world may never see another Nelson Mandela, he has inspired countless men and women throughout the world to live more courageous and honest lives."
Brazilian President Dilma Rousseff mourned the death of Mandela, hailing him as an example for those fighting for justice and peace.
"The example of this great leader will guide all those who fight for social justice and peace in the world," she said in a statement.
Mandela actors speak out
Two actors who have played Mandela on film paid tribute on Thursday to the late icon - as experts said his death will boost the box office fortunes of a just-released film.
"Today the world lost one of the true giants of the past century," said Morgan Freeman, who played the leader in Oscar-nominated 2009 film "Invictus," directed by Clint Eastwood.
"Nelson Mandela was a man of incomparable honour, unconquerable strength, and unyielding resolve - a saint to many, a hero to all who treasure liberty, freedom and the dignity of humankind," he added in a statement released by his publicist.
Idris Elba, who plays Mandela in the just-released "Mandela: Long Walk to Freedom," said: "What an honour it was to step into the shoes of Nelson Mandela and portray a man who defied odds, broke down barriers, and championed human rights before the eyes of the world.
"My thoughts and prayers are with his family.
The timing of the movie's release - it opened on 29 November in the United States - will likely boost audiences. It is due out in a string of European countries in the coming months, but that could change after Mandela's death at age 95.
"Sadly for anyone that dies, it's never a good time. But honestly, the timing couldn't be better for Weinstein Co." Jeff Bock of box office tracker Exhibitor Relations told AFP, referring to the film's distributors.
"This is as timely as it gets."
He joked that even legendary Hollywood producer Harvey Weinstein would struggle to organise a more effective publicity boost.
"Harvey Weinstein has pulled some great ploys to get his films in the news in the past, but this is even beyond his scope," he said.