Johannesburg (CNN) -- They gathered in the tens of thousands -- presidents, prime ministers, royals, celebrities and ordinary South Africans -- all united to say farewell to a man hailed as a global symbol of reconciliation.
In what has been billed as one of the largest gatherings of global leaders in recent history, representatives from around the world joined street sweepers, actors and religious figures to pay tribute to Nelson Mandela.
From President Barack Obama to Cuba's Raul Castro, praise came from all sides in a four-hour memorial service at Johannesburg FNB stadium for the revered statesman, who died Thursday at age 95.
"We will never see the likes of Nelson Mandela again," Obama said in a speech to roaring cheers.
Nelson Mandela, the prisoner-turned-president who reconciled South Africa after the end of apartheid, died on December 5, 2013. He was 95.
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The hearse carrying former South African President Nelson Mandela leaves the Union Buildings after the final day of his lying in state in Pretoria, South Africa, on Friday, December 13.
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"To the people of South Africa -- people of every race and every walk of life -- the world thanks you for sharing Nelson Mandela with us," he said, calling him a "giant of history."
Gray skies and pouring rain throughout the service did little to dampen the mood.
Huge poster pictures of Mandela hung around the stadium. In that same place 23 years earlier, Mandela had delivered his first speech after he was released from prison, hailed by supporters as the hope of a new South Africa.
Also known as Soccer City, the stadium was where Mandela made his last public appearance at the World Cup final in July 2010.
On Tuesday, many people carried banners honoring "Madiba," Mandela's traditional clan name. Others were draped in materials covered with his face or the green, yellow, black, red and blue colors of the South African flag.
Some had skipped work and lined up for hours to secure seats so that they could pay their respects to a man who's considered a moral compass and South Africa's symbol of the struggle against racial oppression.
"There is no one like Madiba. He was one of a kind," South African President Jacob Zuma said.
"Everyone has had a Mandela moment when this world icon has touched their lives."
'Tata Madiba'
The memorial service began with a marching band playing the national anthem.
The joyous cries died down as speeches from Mandela's family and friends, members of the African National Congress, as well as a fellow Robben Island prison inmate, began.
Anguished faces listened quietly as a sorrowful chant to "Tata Madiba" filled the air. "Tata" means "father" in Mandela's Xhosa tribe.
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Mandela's gift for uniting foes across political and racial divides was still evident at the service.
Walking up the stairs onto the stage to deliver his speech, Obama shook hands with Castro, an unprecedented gesture between the leaders of two nations that have been at loggerheads for more than half a century.
He earlier gave a warm greeting to Brazilian President Dilma Rousseff, kissing her on both cheeks, despite recent tension between the two countries over reports the U.S. government was spying on her communications.
Obama, who like Mandela was his nation's first black president, has cited Mandela as his own inspiration for entering politics.
He said his death should prompt self-reflection.
"With honesty, regardless of our station or our circumstance, we must ask: How well have I applied his lessons in my own life?" Obama said.
"It is a question I ask myself, as a man and as a president. We know that like South Africa, the United States had to overcome centuries of racial subjugation. As was true here, it took sacrifice -- the sacrifices of countless people, known and unknown -- to see the dawn of a new day."
The presidents of Namibia, India, Cuba and South Africa were also designated speakers, as were Roussef and Chinese Vice President Li Yuanchao.
"South Africa has lost a hero, they have lost a father. The world has lost a beloved friend and mentor," United Nations Secretary-General Ban Ki-moon said to loud cheers.
"Nelson Mandela was more than one of the greatest leaders of our time, he was one of the greatest teachers. And he taught by example."
The stadium, which can seat around 90,000 people, was not full, and speeches were hard to hear at times. But the celebratory mood was evident as thousands clapped and waved South African flags throughout the service.
Presidents and celebrities
Foreign guests included British Prime Minister David Cameron, the Prince of Wales, French President Francois Hollande and Liberian President Ellen Johnson Sirleaf.
"It means a lot because it really is to say goodbye to an extraordinary man and to commemorate someone who did so much not just for South Africa, but also for the world in terms of the inspiration that he gave," Cameron told CNN's Christiane Amanpour.
Nobel Peace Prize laureate Archbishop Desmond Tutu and members of The Elders, a group of retired statesmen founded by Mandela and others, were also in attendance, including former U.N. Secretary-General Kofi Annan and former U.S. President Jimmy Carter.
The crowds cheered loudly and clapped as a huge screen showed famous faces, such as F.W. de Klerk, the last leader of white South Africa, who shared a Nobel Peace Prize with Mandela for helping to end apartheid.
Mandela's widow, Graca Machel, and his former wife Winnie Mandela embraced and kissed as they arrived.
The world of entertainment also was well represented, with South African actress Charlize Theron and U2's Bono in attendance. Celebrity guests also included model Naomi Campbell.
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Tight security
With 91 heads of state attending, security was tight.
Working off plans developed for years in secret, the South African government planned to use an elite military task force, sniper teams and canine teams to help secure the stadium, CNN's Arwa Damon reported Monday. In addition, helicopters and military jets frequently flew overhead.
U.S. officials said they were satisfied with security arrangements.
The event rivaled other significant state funerals in recent decades, such as that of former British Prime Minister Winston Churchill in 1965 and the 2005 funeral of Pope John Paul II, which attracted some 2 million people to Rome -- among them four kings, five queens, at least 70 presidents and prime ministers and the leaders of 14 other faiths.
Security was also stepped up outside Mandela's home, where crowds danced under umbrellas. Some even enjoyed the rain, jumping into puddles.
"We want to respect our father of the nation, our father of the country. That is why we left work to pay that respect to him," one South African told CNN.
State funeral on Sunday
Crews had worked overtime Monday to prepare the stadium for the service.
The government set up overflow locations at stadiums and other facilities throughout the country.
With private vehicles banned from the area around the stadium, the government pressed buses from around the country into service and stepped up train service to move the crowds.
In Soweto township, where Mandela lived before he was imprisoned for 27 years, people waited for three hours for buses to take them to the stadium. Unfazed by the wait, they sang and danced.
While Tuesday's memorial is the first major event honoring Mandela since his death, it won't be the last.
A state funeral will be held Sunday in Mandela's ancestral hometown of Qunu in South Africa's Eastern Cape province.
Other speakers at Tuesday's service included Mandela's friend and fellow anti-apartheid activist Archbishop Tutu
"We promise God that we are going to follow the example of Nelson Mandela," he said to loud cheers.
Mandela family members, including his grandchildren, also spoke.
Paying tribute to his uncle, Gen. Thanduxolo Mandela said his family has gone through waves of grief, sorrow and anguish after his death.
But "today, more than any other feeling my family holds is thankfulness for that wonderful life," he said, also giving thanks for the outpouring of respect from around the world
"This universal show of unity is a true reflection of all that Madiba stood for -- peace, justice, unity of all mankind. Let us pledge to keep Madiba's dream alive."
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CNN's Michael Pearson, Athena Jones, Holly Yan, Chris Cuomo, Kim Norgaard, Robin Curnow, Arwa Damon Errol Barnett and David McKenzie contributed to this report.
Mandela became president of the African National Congress Youth League in 1951.
Mandela poses for a photo, circa 1950.
Mandela poses in boxing gloves in 1952.
Mandela in the office of Mandela & Tambo, a law practice set up in Johannesburg by Mandela and Oliver Tambo to provide free or affordable legal representation to black South Africans.
From left: Patrick Molaoa, Robert Resha and Mandela walk to the courtroom for their treason trial in Johannesburg.
Mandela married his second wife, social worker Winnie Madikizela, in 1958. At the time, he was an active member of the African National Congress and had begun his lifelong commitment to ending segregation in South Africa.
Nelson and Winnie Mandela raise their fists to salute a cheering crowd upon his 1990 release from Victor Verster Prison. He was still as upright and proud, he would say, as the day he walked into prison 27 years before.
A jubilant South African holds up a newspaper announcing Mandela's release from prison at an ANC rally in Soweto on February 11, 1990. Two days later, more than 100,000 people attended a rally celebrating his release from jail.
Mandela and Zambian President Kenneth Kaunda arrive at an ANC rally on March 3, 1990, in Lusaka, Zambia. Mandela was elected president of the ANC the next year.
After his release in 1990, Mandela embarked on a world tour, meeting U.S. President George H.W. Bush at the White House in June.
At his Soweto home on July 18, 1990, Mandela blows out the candles on his 72nd birthday cake. It was the first birthday he celebrated as a free man since the 1960s.
Mandela and his wife react to supporters during a visit to Brazil at the governor's palace in Rio De Janeiro, on August 1, 1991.
South African President Frederik de Klerk, right, and Mandela shared a Nobel Peace Prize in 1993 for their work to secure a peaceful transition from apartheid rule.
Mandela votes for the first time in his life on March 26, 1994.
On April 27, 1994, a long line of people snake toward a polling station in the black township of Soweto outside of Johannesburg in the nation's first all-race elections.
Mandela in Mmabatho for an election rally on March 15, 1994.
Mandela was elected president in the first open election in South African history on April 29, 1994. He's pictured here taking the oath at his inauguration in May, becoming the nation's first black president.
Mandela, left, cheers as Springbok Rugby captain Francois Pienaar holds the Webb Ellis trophy high after winning the World Cup Rugby Championship in Johannesburg on June 24, 1995.
After one term as president, Mandela stepped down. Thabo Mvuyelwa Mbeki, at right, was sworn in as his replacement in June 1999.
Mandela sits outside his former prison cell on Robben Island on November 28, 2003, ahead of his AIDS benefit concert at Green Point Stadium in Cape Town. He was sent to the infamous prison five miles off the coast of South Africa, where he spent 18 of his 27 years behind bars.
Mandela shows something to a group of international journalists visiting the Nelson Mandela Foundation in Johannesburg in May 2004.
Mandela sits with his wife, Graca Machel, and his grandchildren at his son's funeral on January 15, 2005. He disclosed that his son, Makgatho Lewanika Mandela, had died of AIDS and said the disease should be given publicity so people would stop viewing it as extraordinary.
The "46664 Arctic" benefit concert was held in Tromso, Norway, on June 11, 2005. 46664 was Mandela's identification number in prison. Here, artists who performed at the event surround him.
Mandela attends an HIV/AIDs concert in Johannesburg on February 17, 2005.
Former U.S. President Bill Clinton leans down to whisper to former South African President Nelson Mandela during a visit to the Nelson Mandela Foundation on July 19, 2007, in Johannesburg.
A bronze statue of Mandela was unveiled in Parliament Square in London on August 29, 2007. The 9-foot statue faces the Houses of Parliament.
Mandela leaves the InterContinental Hotel after a photoshoot with celebrity photographer Terry O'Neil on June 26, 2008, in London.
Mandela meets in 2009 with international children as part of his 46664 Foundation.
Nelson Mandela and his third wife, Graca Machel, arrive at the 2010 World Cup before the final match between Netherlands and Spain on July 11, 2010, at Soccer City Stadium in Soweto.
Then-U.S. Secretary of State Hillary Clinton meets with Mandela at his home in Qunu, South Africa, on August 6, 2012.
The national flag-draped coffin of the former South African President is carried down steps of the Union Buildings at the end of the third and final day of lying in state on December 13.
South African Naval personnel stand guard around Mandela's casket as he is carried to the Union Buildings on the final day of his lying in state on December 13.
A cheering man climbs up a fence after the casket of Mandela passed on its way to the Union Buildings on December 13.
A rainbow forms over the Union Buildings in Pretoria on Thursday, December 12, after the public viewing of Mandela's casket.
Mandela's funeral procession drives toward the Union Buildings on December 12. Each morning his remains were transported from the mortuary to the government buildings.
People queue to catch a bus to see the remains of Nelson Mandela at the Union Buildings on December 12.
People attend the memorial service for former South African President Nelson Mandela at FNB Stadium in Johannesburg on Tuesday, December 10. Thousands of South Africans and more than 90 heads of state gathered to honor the revered leader, who died Thursday, December 5. He was 95.
Mandela supporters make their way to the stadium.
A group of people gets a ride to the event.
Former members of the armed wing of the African National Congress run through the streets on their way to the memorial service.
People in the stadium take shelter from the rain.
A young boy holds up a flag honoring "Madiba," Mandela's traditional clan name.
People take shelter under blankets and umbrellas during the memorial service.
Cuban leader Raul Castro addresses the state memorial service for Mandela.
Denmark's Prime Minister Helle Thorning-Schmidt snaps a selfie with British Prime Minister David Cameron and U.S. President Barack Obama.
A South African soldier watches the flame of the torch before entering the field during the memorial service.
President Barack Obama addresses the crowd during the memorial service.
Obama shakes hands with Cuban President Raul Castro just before speaking.
South Africans cheer during the memorial service.
Dignitaries from all over the world stand at the beginning of the memorial service.
A boy looks up during the memorial service at FNB Stadium. He has "RIP Nelson Mandela" painted on his face.
A man displays a sign with pictures of Mandela during the memorial service.
People take shelter under umbrellas at FNB Stadium.
A man raises his fist during the memorial service.
This handout photo released by Mexican presidency press office shows (L-R) Spanish Prince Felipe de Borbon, Mexican President Enrique Pena Nieto an Canadian Prime Minister Stephen Harper on December 10, 2013, while attending the funeral of Nelson Mandela at Soccer City stadium in Johannesburg, South Africa. AFP PHOTO/ MEXICAN PRESIDENCYHO/AFP/Getty Images
Mandela's ex-wife, Winnie Madikizela-Mandela, left, and his widow, Graca Machel, right, sit near each other during the memorial service.
Mandela's face looms large on a billboard inside FNB Stadium.
Girls dance during the memorial service at FNB stadium.
Mourners pause for a prayer during the memorial service.
Mandla Mandela, left, grandson of Nelson Mandela, attends the memorial service.
Queen Rania of Jordan speaks with former President George W. Bush and his wife, Laura, during the memorial service.
Former Secretary of State Hillary Clinton arrives for the memorial service.
Former Presidents Bill Clinton and George W. Bush wave during the memorial service. Chelsea Clinton is at left.
U.N. Secretary-General Ban Ki-moon, left, and South African President Jacob Zuma stand during the memorial service.
People watch a telecast of the memorial service inside Orlando Stadium in Soweto, which played an important role in the uprisings against apartheid.
Former Archbishop Desmond Tutu, right, arrives with former U.N. Secretary-General Kofi Annan at FNB Stadium.
Singer Bono and actress Charlize Theron attend the memorial service.
People celebrate Mandela at a telecast of the memorial service at Ellis Park in Johannesburg.
People sing and dance at Ellis Park in Johannesburg.
Women draped in flags printed with Mandela's face arrive at FNB Stadium.
Cuban President Raul Castro arrives for the memorial service.
World leaders, including former French President Nicolas Sarkozy, top second left, and French President Francois Hollande, top second right, attend the memorial service.
South Africa Rugby Union captain Francois Pienaar waits for the memorial service to begin.
Mourners wave flags at a telecast of the memorial service at Ellis Park in Johannesburg.
Spain's Prince Felipe arrives at FNB Stadium.
British Prime Minister David Cameron arrives for the memorial service.
Former British Prime Minister John Major arrives for the memorial service.
Members of the public sing and dance as they arrive for the memorial service at FNB Stadium.
People arrive at FNB Stadium before the memorial service.
Members of the public make their way to the memorial service at FNB Stadium.
A man clutches the official program in Johannesburg.
Mourners sing as they take shelter from the rain in the hallways of FNB Stadium.
A man waves a South African flag at FNB Stadium.
People walk around the FNB Stadium in Johannesburg.
