Apartheid was a system of racial discrimination and segregation in South African government. It was formalized in 1948, forming a framework for political and economic dominance by the white population and severely restricting the political rights of the black majority.
Between 1960 and 1990, the African National Congress and other mainly black opposition political organisations were banned. As the National Party cracked down on black opposition to apartheid, most leaders of ANC and other opposition organisations were either imprisoned or went into exile.
However, increasing local and international pressure on the government, as well as the realisation that apartheid could neither be maintained by force forever nor overthrown by the opposition without considerable suffering, eventually led both sides to the negotiating table.