A Nobel laureate
In 1993, Mandela and then-South African President F.W. de Klerk jointly won the Nobel Peace Prize.
The iconic leader was elected the nation's first black president a year later, serving only one term, as he had promised.
Even as he has faded from the spotlight, he remains popular and is considered a hero of democracy in the nation. Last year, South Africa launched a new batch of banknotes with a picture of a smiling Mandela on the front.
His impact extends far beyond South Africa. After he left office, he mediated conflicts in Africa and the Middle East.
Word of his worsening health drew global expressions of concern.
"We have seen the latest reports from the South African government that former President Mandela is in critical condition," Caitlin Hayden, a U.S. National Security Council spokeswoman, said in a statement. "Our thoughts and prayers are with him, his family and the people of South Africa."