World leaders, from US President Barack Obama to Cuba's Raul Castro, are paying homage to Nelson Mandela at a mass memorial in South Africa that recalls his gift for bringing enemies together across political and racial divides.
Obama shook the hand of Castro at the memorial, an unprecedented gesture between the leaders of two nations which have been at loggerheads for more than half a century.
Castro smiled as Obama shook his hand on the way to the podium to make a speech at the commemoration for former South African President Mandela, one of the world's greatest peacemakers who died on Thursday.
Castro was also among the designated orators at a Johannesburg football stadium where 23 years earlier Mandela - freshly freed from apartheid jail - was hailed by cheering supporters as the hope for a new South Africa.
'Last great liberator'
In his address, Obama said Nelson Mandela earned his place in history through struggle, shrewdness, persistence and faith, comparing him to Mahatma Gandhi, Martin Luther King Jr. and Abraham Lincoln.
Obama urged the world to act on Mandela's legacy by fighting inequality, poverty and racism. He said progress in the US and South Africa mustn't cloud the fact there's still work to be done.
He said "South Africa shows us that we can change".
Obama called Mandela the last great liberator of the 20th century, and said he thought about how to apply Mandela's lessons to himself as a man and as president.
Al Jazeera's Mike Hanna, reporting from Johannesburg said that all the speakers selected were leaders and statesmen from countries that had previously been under colonialist rule.
"There is no head of state from the UK or the commonwealth speaking at the funeral," he said. "The list of speakers displays South Africa's political orientation away from the west.
"Each of the six selected speakers have had a history of colonialist rule."
Obama's Air Force One arrived at Waterkloof air force base near Pretoria on Tuesday morning after a 16-hour flight from Washington DC.
Obama was asked to speak because of the close relationship between the US and Mandela.
The US president and his wife Michelle were followed down the steps by former president George W Bush and his wife Laura. Two other former US presidents, Bill Clinton and Jimmy Carter, were arriving separately.
|Follow our coverage of Mandela's death and legacy
Coinciding with UN designated Human Rights Day, the memorial service for Mandela in the 95,000-seat Soccer City stadium is the centrepiece of a week of mourning for the globally-admired statesman, who died on Thursday aged 95.
A light rain fell on Tuesday as thousands of mourners gathered at the stadium in Soweto, the Johannesburg township that was a stronghold of support for the anti-apartheid struggle that Mandela embodied.
Singing, joyous crowds are swelling in the stands despite the rain. Workers still were welding at a VIP area as the first spectators arrived.
Police have promised tight security, and are patrolling a wide perimeter around the stadium. Even so, the first crowds entered the stadium without being searched.
The fact that the visiting leaders - more than 90 are expected - include some from nations still locked in antagonism, such as Cuba and the US, adds piquancy and resonance to the homage being held at the gigantic bowl-shaped stadium, the venue of the 2010 World Cup final.
Zimbabwean President Robert Mugabe and former British Prime Minister Tony Blair will both be there. Blair has called Mugabe a dictator who should have been removed from power.
Mugabe has called Blair an imperialist and once told him to "go to hell". Such antagonisms will be put on mute on Tuesday as the life of someone who put his faith in reconciliation into practice to successfully unite a multi-racial nation is remembered.
"What he did in life, that's what he's doing in death, he's bringing people together from all walks of life, from the different sides of opinion, political belief, religion," Zelda la Grange, Mandela's former personal assistant, told Reuters news agency.
Israel's top leaders will be conspicuous by their absence at the memorial, skipping the ceremony for the anti-apartheid hero whom Palestinians have always viewed as their comrade in the struggle for freedom.
Neither Prime Minister Benjamin Netanyahu nor President Shimon Peres will attend the event, officials said on Monday, citing costs and health reasons.