Dignitaries and world leaders have joined tens of thousands of people gathering at the Johannesburg FNB Stadium to celebrate the life of Nelson Mandela in a memorial service.
The Prime Minister David Cameron is among those who have joined Mr Mandela’s surviving predecessors at the special commemoration service, which started at approximately 10am GMT today.
Rain continued to pour during the ceremony as Cyril Ramaphosa, deputy president of the ANC made repeated calls for "discipline" from the crowd and "respect" following loud boos when cameras showed South African president Jacob Zuma on screen. In heavy contrast, applause rang out from across the stadium when US President Barack Obama was presented to the audience.
Mr Obama was met with resounding cheers when he took to the stage to pay tribute to the former South African president, who he said was "a giant of history, who moved a nation towards justice, and in the process, moved billions around the world."
He told the audience: "His struggle was your struggle, his triumph was your triumph. Your dignity and your hope found expression in his life, and your freedom, your democracy is his cherished legacy."
He said Mr Mandela not only freed the prisoners, he freed the jailers as well.
"He was not a bust made of a marble, he was a man of flesh and blood, a son and a husband, a father and a friend, and that’s why we learnt so much from him, and why we can learn from him still."
He added: "Mandela taught us the power of action, but he also taught us the power of ideas. He understood that ideas cannot be contained by prison walls, or extinguished by a snipers bullet."
He cited the South African concept of "ubuntu", the idea that humanity is bound together, and said Mr Mandela "understood the ties that bind the human spirit".
Mr Obama criticised the world leaders "who claim solidarity with his struggle for freedom but do not tolerate dissent from their own people", and said "there are too many of us on the side lines comfortable with complacency or cynicism".
Drawing his speech to a close, he told the thousands gathered: "We will never see the likes of Nelson Mandela again".
The US President's sentiments were echoed by his South African counterpart, who delivered the service's keynote address.
Mr Zuma was again booed as he prepared to speak, and the ceremony organisers had no choice but to interject with a praise song from the choir while dissenting voices died down.
After a pause, the country's president told the assembled crowd of more than 90,000 people: "Fellow mourners, there is no one like Madiba. He was one of a kind."
Mr Zuma described Mandela as a "fearless freedom fighter", and said: "Madiba laid the foundation for a better life for all - which was the rallying cry of his presidency."
As whistling and singing continued to ring out through the stadium, Mr Zuma spoke in English, giving an account of South Africa's history under Mandela.
After briefly addressing the country in Zulu, he then turned to plans for the future, saying: "Compatriots and friends, today Madiba is no more. He leaves behind a nation that loves him dearly, a continent that is truly proud to call him African.
"He leaves the people of the world, who embraced him as their own beloved icon. Most importantly, he leaves behind a deeply entrenched legacy of freedom, human rights and democracy in this nation.
"United in our diversity, we will continue working to build a nation free of poverty, hunger, homelessness and inequality.
"We will continue working to fulfil his desire for a better Africa."
Earlier, President Castro spoke via a translator and said Cuba has had the privilege of fighting alongside the African nations.
He said: “We shall never forget Mandela's moving homage to our common struggle, when on the occasion of his visit to our country he said, and I quote, ‘the Cuban people have a special place in the heart of the peoples of Africa'."
He remembered the “ongoing affection” Mandela had for Fidel Castro, which he described as a “symbol of the fraternal relations between Africans and Cubans”.
The service opened with the stadium crowd singing the national anthem led by a choir, followed with interfaith prayers opened by Chief Rabbi Warren Goldstein. Former Robben Island inmate and friend Andrew Mlangeni then took to the stage to pay tribute to the man he said "created hope when there was none".
"Madiba's greatness as a leader stems from his humility and his great belief in collective leadership," he said.
Family member General Thanduxolo Mandela said: "Our generation needs new leaders in the calibre of Madiba". His grandchildren paid tribute to their grandfather in eulogies. UN Secretary General Ban Ki-Moon said South Africa has lost a hero, and added: "We have lost a father". He continued: "Nelson Mandela is at rest, his long walk complete."
The Nobel Peace Prize winner died aged 95 last Thursday following a long term lung infection. The service comes as part of a series of commemorations taking place before Mr Mandela's funeral on Sunday.
Mr Mandela's former wife Winnie Madikizela Mandela joined his widow Graca Machel and other members of his family at the stadium.
The football arena, where Mr Mandela made his last public appearance in 2010, has a capacity of 95,000, although bad weather is believed to have contributed to the many empty seats. The service is also being shown at three overflow stadiums in Dobsonville, Orlando and Rand.
Russian President Vladimir Putin signed a book of condolence in the South African embassy in Moscow earlier on Monday.
Deputy Prime Minister Nick Clegg and Labour leader Ed Miliband are in attendance, along with former Prime Ministers Sir John Major, Tony Blair and Gordon Brown.
In a Parliamentary tribute on Monday, Mr Cameron said Mr Mandela was a “towering figure in our lifetime” and added: “When looking back over history it can be easy to see victories over prejudice and hatred as somehow inevitable.
"As the years lengthen and events recede, it can seem as though the natural tide of progress continually bears humanity ever upwards, away from brutality and darkness and towards something better. But it is not so.
"Progress is not just handed down as a gift, it is won through struggle - the struggle of men and women who believe things can be better, who refuse to accept the world as it is but dream of what it can be. Nelson Mandela was the embodiment of that struggle.
"He did not see himself as the helpless victim of history - he wrote it."
Francois Hollande of France, Palestinian leader Mahmoud Abbas, vice president of China Li Yuanchao and India's President Pranab Mukherjee are all in attendance at the four-hour long service, along with Zimbabwe President Robert Mugabe.
After the memorial service Mr Mandela's body will lie in state at South Africa's seat of government, the Union Buildings in Pretoria, until he is laid to rest in a state funeral at his hometown of Qunu in the Eastern Cape.