F.W. De KlerkDe Klerk, F.W. /də ˈklɜːk $ -ˈklɜːrk/ (1936–) the president of South Africa from 1989 to 1994. He made many political changes and finally ended the system of apartheid. In 1990 he allowed the ANC to become a legal organization again, and let Nelson Mandela out of prison. He and Mandela won the Nobel Peace Prize in 1993.