On June 12, 1964, political activist Nelson Mandela (Sidney Poitier) is sentenced to life in prison for treason against the South African state. During the years of his incarceration at Robben Island, Mandela rises to become the symbolic leader of black South Africa. Meanwhile, Mandela's one-time ideological foil, South Africa's white president, F.W. de Klerk (Michael Caine), puts into place reforms that bring an end to his country's decades-old policy of racial segregation: apartheid.