Leaders from around 70 countries are taking part in an open-air memorial service for Nelson Mandela amid a heavy downpour at a stadium in Johannesburg.
An estimated 100,000 people were expected to fill the massive stadium, the site of the final of the 2010 football World Cup.
U.S. President Barack Obama, British Prime Minister David Cameron, and French President Francois Hollande are just a few of the world leaders who are attending.
At the ceremony, Obama called Mandela a "giant of history who moved a nation toward justice." He thanked the people of South Africa "for sharing Nelson Mandela with us."
WATCH: U.S. President Barack Obama praised Nelson Mandela as the last great liberator of the 20th century and said the late anti-apartheid leader taught that reconciliation was "not a matter of ignoring a cruel past, but a means of confronting it with inclusion."
UN Secretary-General Ban Ki-moon addressed the crowd before Obama.
Ban said of Mandela, "He showed the awesome power of forgiveness -- and of connecting people with each other...the true meaning of peace."
Ban looked on all the leaders and dignitaries present in the stadium and said, "He [Mandela] has done it again," adding, "Look around this stadium and this stage. We see leaders representing many points of view, and people from all walks of life. All here, united."
African National Congress Vice President Cyril Ramaphosa was among the first speakers and said, "When it rains when you are buried, it means your gods are welcoming you and the gates of heaven are most probably open as well."
Other speakers at the memorial included Mandela's longtime friend, Nobel Peace Prize winner Bishop Desmond Tutu.
South African authorities rushed on December 9 to deal with the complex security and logistical challenges of hosting what promised to be one of the largest and most prominent gatherings of world dignitaries in generations.
The antiapartheid leader and South Africa's first black president died on December 5.
He was 95.
Mandela will be buried in a state funeral in his hometown on December 15.
Based on reporting by AP, Reuters, dpa, and BBC