Apartheid, which means "being apart" in Afrikaans, was the system of racial separation that was implemented in South Africa after the Second World War (although it had roots in the earlier twentieth century.) Like segregation in the American South, it was cast as an enlightened measure to keep mutually antagonistic races separate, but it was, as was always clear, about maintaining white supremacy in the country. It outlawed marriage and sex between the races, and actually forced black farmers off of lands designated for whites. Apartheid was enforced by state-implemented violence, with white policemen violently putting down peaceful protests against the institution, especially beginning in the 1970s. This system, which finally came to an end in 1994 under the leadership of F.W. de Klerk, was consistently challenged by black South Africans led by Nelson Mandela (who spent decades in prison for his efforts) and others. It was among the most flagrantly racist legal and social systems to exist anywhere in the world in the late twentieth century.