The 1950s were to bring increasingly repressive laws against black South Africans and its corollary - increasing resistance. The Group Areas Act, rigidifying the racial division of land, and the Population Registration Act, which classified all citizens by race, were passed in 1950. The pass laws, restricting black movement, followed in 1952. The Separate Amenities Act of 1953 introduced "petty apartheid" segregation, for example, on buses and in post offices. In that year Malan retired and JG Strijdom became Prime Minister.

Black reaction to increasingly suppressive racist legislation came in the form of the mass mobilisation of the Defiance Campaign, commencing in 1952. Based on non-violent resistance, it nevertheless led to the jailing of thousands of participants. The result was to increase unity among resistance groups with the forming of the Congress Alliance, which included black, coloured, Indian and white resistance organisations as well as the South African Congress of Trade Unions.

In 1954 a campaign against the deliberately inferior Bantu Education System was launched. The following year saw two of the most significant events of the decade. One established how far the government was willing to go to pursue its aims. Unable to gain the two-thirds majority required by the 1910 constitution to remove coloureds from the common voters' roll, the government changed the composition of the Senate by increasing its size (and consequently Nationalist majority) to give it the required majority in a joint sitting of the Senate and the House of Assembly.

The second watershed moment came when, after an ANC campaign to gather mass input on freedom demands, the Freedom Charter - based on the principles of human rights and non-racialism - was signed on June 26 1955 at the Congress of the People in Soweto. Reaction was swift: the following year 156 leaders of the ANC and its allies were charged with high treason. The longest trial in South African history was to lead to the acquittal of all of accused in 1961.

Strijdom died in 1958 and was succeeded by HF Verwoerd. The following year representatives of black Africans were removed from both houses of parliament and the Cape provincial council; on the other side of the political fence, the Pan-Africanist Congress (PAC), founded by Robert Sobukwe, broke away from the Congress Alliance. The stage was set for the even more polarised '60s.