South Africa has begun a week of remembrance for Nelson Mandela, a former president and globally admired leader who died at home Dec. 5 at age 95. He had been imprisoned 27 years for opposing the white-led government’s policy of racial separation and undemocratic rule. He’s widely considered “the father” of modern South Africa because he broke the chains of racism and successfully urged national forgiveness for those who persecuted him.

Dignitaries at a memorial service Tuesday will include President Obama and three U.S. ex-presidents (Jimmy Carter, George W. Bush, Bill Clinton), plus 26 members of Congress. The service at a stadium near Johannesburg is expected to be among the largest gatherings of world leaders in history. A state funeral follows Sunday, with about 9,000 people expected.

Mandela’s huge, lasting achievement was to lead a movement that changed South Africa from a nation ruled harshly by its white minority into a democracy where all races vote and have elected a series of black-led governments. The previous policy, imposed in 1948 by Dutch colonists, was called apartheid – which means “apart-hood” (separating the races) and is pronounced a-PARR-tied. It was eased and then abandoned by the country’s last white president, Frederik Willem de Klerk, who in 1990 freed Mandela from prison. The longtime enemy of the state was elected head of state four years later in his country’s first democratic election. In recognition of the peaceful transition, he and de Klerk shared the 1993 Nobel Peace Prize "for their work for the peaceful termination of the apartheid regime, and for laying the foundations for a new democratic South Africa."

S. African president says: "We should, while mourning, also sing at the top of our voices, dance and do whatever we want to do. As South Africans, we sing when we are happy and we also sing when we are sad to make ourselves feel better.” -- Jacob Zuma

Clergyman says: “Madiba [Mandela’s nickname] paved the way for a better future, but he cannot do it alone. He needs you, me and the world to continue in the foundation he laid.” -- Father Sebastian Rossouw, parish priest in Soweto, site of Tuesday’s memorial

Nelson Mandela said: ”We shall build the society in which all South Africans, both black and white, will be able to walk tall, without any fear in their hearts, assured of their inalienable right to human dignity — a rainbow nation at peace with itself and the world.” – First speech as president, May 10, 1994