Eulogy: U.S. President Barack Obama acknowledges the crowd as he delivers his speech at the memorial service for Nelson Mandela in Johannesburg

Eulogy: U.S. President Barack Obama acknowledges the crowd as he delivers his speech at thememorial service for Nelson Mandela in Johannesburg

Tens of thousands of South Africans have joined dozens of world leaders for thenational memorial service for former President Nelson Mandela.

The service is being held in front of a vociferous crowd in the FNB stadium in Johannesburg.

US President Barack Obama said Mr Mandela was a “giant of history”, adding: “The world thanks you for sharing Nelson Mandela with us”.

The former South African president died last Thursday, aged 95.

Family affair: (front row) Mr Mandela's daughters Zindzi, Zenani and Makaziwe Mandela, ex-wife Winnie Mandela Madikizela and widow Graca Machel before the service

Family affair: (front row) Mr Mandela’s daughters Zindzi, Zenani and Makaziwe Mandela, ex-wifeWinnie Mandela Madikizela and widow Graca Machel before the service

The country is observing a series of commemorations leading up to the funeral on Sunday.

The memorial service is one of the biggest gatherings of international dignitaries in recent years.

There had been fears people would be turned away, but the heavy rain left areas of the 95,000 capacity stadium empty.

Introducing the proceedings, the master of ceremonies, Cyril Ramaphosa, said that Mr Mandela’s “long walk is over… and he can finally rest”.

The first speaker, friend and fellow Robben Island inmate Andrew Mlangeni, said Mr Mandela had “created hope when there was none”.

Historic: The handshake between the leaders of the two Cold War enemies came during a ceremony that focused on Mandela's legacy of reconciliation

Historic: The handshake between the leaders of the two Cold War enemies came during a ceremony that focused on Mandela’s legacy of reconciliation

Obama said Nelson Mandela had taught the world the power of action and the power of ideas, and that it had taken a man like Mr Mandela to free not only the prisoner but also the jailer.

Mr Obama said: “We will never see the likes of Nelson Mandela again. While I will always fall short of Madiba (Mr Mandela’s clan name), he makes me want to be a better man.”

On his way to the podium, President Obama shook hands with Cuban President Raul Castro, an unprecedented gesture between the leaders of two nations that have been at loggerheads for more than half a century.

Paying tribute: World leaders converged on the FNB Stadium in Soweto, the Johannesburg township that was a stronghold of support for the anti-apartheid struggle that Mandela embodied

Paying tribute: World leaders converged on the FNB Stadium in Soweto, the Johannesburg township that was a stronghold of support for the anti-apartheid struggle that Mandela embodied

In his address, Mr Castro paid tribute to Mr Mandela as the “ultimate symbol of dignity and the revolutionary struggle”.

Under his brother, Fidel, Cuba was a staunch critic of apartheid, and Mr Mandela had expressed gratitude for that support.

In his speech, UN Secretary General Ban Ki-moon said there was “sorrow for a mighty loss and celebration of a mighty life”.

He said: “South Africa has lost a hero, it has lost a father… He was one of our greatest teachers. He taught by example. He sacrificed so much and was willing to give up all he had for freedom and democracy.