The Convention for a Democratic South Africa ( CODESA ) began in December 1991 at the Johannesburg World Trade Centre , attended by 228 delegates from 19 political parties . Although Cyril Ramaphosa led the ANC 's delegation , Mandela remained a key figure , and after de Klerk used the closing speech to condemn the ANC 's violence , he took to the stage to denounce de Klerk as the " head of an illegitimate , discredited minority regime " . Dominated by the National Party and ANC , little negotiation was achieved . CODESA 2 was held in May 1992 , at which de Klerk insisted that post-apartheid South Africa must use a federal system with a rotating presidency to ensure the protection of ethnic minorities ; Mandela opposed this , demanding a unitary system governed by majority rule . Following the Boipatong massacre of ANC activists by government-aided Inkatha militants , Mandela called off the negotiations , before attending a meeting of the Organisation of African Unity in Senegal , at which he called for a special session of the UN Security Council and proposed that a UN peacekeeping force be stationed in South Africa to prevent " state terrorism " . Calling for domestic mass action , in August the ANC organised the largest-ever strike in South African history , and supporters marched on Pretoria
Boipatong massacre
Boipatong massacre
Nelson Mandela