Nelson Mandela, who was instrumental in ending apartheid in South Africa, is celebrating his 90th birthday on Friday.
After a series of public appearances around the world over the past few weeks, the former president is spending the day at his village home with his family.
Former South African President FW de Klerk has led tributes to the man who succeeded him.
Mr Mandela was jailed for 27 years as a head of the banned ANC before he was made the country's first black leader.
Since stepping down as president in 1999, Mr Mandela has become South Africa's highest-profile ambassador, campaigning against HIV/Aids and helping to secure his country's right to host the 2010 football World Cup.
In 2004, at the age of 85, Mr Mandela retired from public life to spend more time with his family and friends.
"We are honoured that you wish to celebrate the birthday of a retired old man who no longer has power or influence," Mr Mandela says in a special pre-recorded radio broadcast.
Mr de Klerk, who was awarded the 1993 Nobel Peace Prize along with Mr Mandela, described him as one of the greatest figures of the 20th Century.
"After his inauguration, Nelson Mandela used his personal charm to promote reconciliation and to mould our widely diverse communities into an emerging multicultural nation," he says.
"This, I believe, will be seen as his greatest legacy."
Friday also marks 10 years since Mr Mandela married his third wife, Graca Machel.