10 December 1993
Then President F.W. de Klerk, the last president of the white minority rule who abandoned the unsustainable and untenable apartheid system towards a non-racial and democratic South Africa. This meant the release of anti-apartheid activist and African National Congress leader Nelson Mandela. Mandela and de Klerk were jointly awarded the Nobel Peace Prize on 10 December 1993. The award was a recognition for their efforts in achieving a peaceful transformation from an apartheid regime to democracy.
References

BBC News, Nelson Mandela and FW de Klerk, from BBC News [online], Available at news.bbc.co.uk [Accessed: 18 October 2013]|Nobel Prize, The Nobel Peace Prize 1993, from Nobelprize.org, [online], Available at www.nobelprize.org [Accessed: 18 October 2013]