Millions of South African schoolchildren have sung to celebrate Nelson Mandela's 93rd birthday, leading a worldwide chorus of wishes sent to the anti-apartheid icon.
More than 12 million students sang a special version of Happy Birthday before their lessons began.
Mr Mandela also received birthday greetings from South African leaders including President Jacob Zuma and from US president Barack Obama.
In a statement, President Obama called Mr Mandela "a beacon for the global community, and for all who work for democracy, justice and reconciliation".
Mr Mandela, who has retired from public life, was spending the day with his family in his home village of Qunu, about 600 miles south of Johannesburg.
President Zuma visited the house to deliver his greetings in person. Outside the house, a brass band played for several hours in Mr Mandela's honour.
In 2009, Mr Mandela's birthday was declared as an international day devoted to public service.
People around the world have been asked to mark the occasion by giving 67 minutes of their time to work in their local community - one minute for every year of Mr Mandela's public service.
He became South Africa's first black president after spending 27 years in prison for his fight against apartheid and was later awarded a Nobel Peace Prize for his efforts.
Mr Mandela's public appearances have become increasingly rare, though he did appear at the closing ceremony of the World Cup one year ago. Earlier this year, he was in hospital for a few days with an acute respiratory infection.