The policy officially came into effect when South Africa's National Party came to power in 1948. In accordance with the theory of separate development, the government set aside certain areas as homelands for each of the officially recognized African ethnolinguistic groups. Four of the ten homelands were declared independent, although this independence was recognized only by the South African government. Strict residential segregation and many other restrictions were imposed on the majority of blacks who worked in white areas.

The implementation of apartheid over the years involved massive resettlement of peoples and great hardship, and the policy was widely condemned by the international community.
During the late 1970s and 1980s the government relaxed the apartheid laws slightly, lifting some occupational restrictions, desegregating certain public facilities, and repealing (1985) the 1948 law prohibiting intermarriage. The pass laws requiring blacks in white areas to have a permit were repealed in 1986. The Constitution of 1983 gave Coloured and Asians, but not blacks, limited representation in the formerly all-white national Parliament.

In 1990, President F. W. De Klerk committed himself to the abolition of apartheid and said that the homelands would be reincorporated into South Africa. Economic power was still in white hands, however, and much de facto segregation remained. Negotiations to devise a new constitution that would enfranchise all South Africans while protecting white interests began in 1990.

During the 1920s and 1930s a Nationalist-Labour coalition protected Afrikaner interests against rising black competition.
The Nationalists returned to power as a reconstituted party in 1948, determined to take South Africa out of the Commonwealth of Nations (withdrawal occurred in 1961), and ensure white supremacy. After 1948 the party consolidated its power.

The National Party formulated and implemented an apartheid policy of separate racial development to ensure white political and economic domination. This anti-Communist party, strongly supported by the Dutch Reformed church, has long been closely linked to the Broederbond (Band of Brothers), a secret Afrikaner nationalist society founded in 1918 and dedicated to the creation of a separate Afrikaner nation with its own language and culture.

Traditionally exclusively Afrikaner, the party did not elect its first English-speaking members of parliament until the 1960s. Its strongholds are in the former Boer republics, the Orange Free State and the Transvaal.

The National Party banned many opposition groups, including (1960-90) the African National Congress (A.N.C.). In 1990, as landmark talks between de Klerk and ANC leader Nelson Mandela began, de Klerk urged the National Party to open membership to all races and proposed dismantling apartheid as part of a broader settlement.

In the 1940s, the A.N.C. became more militant, sponsoring strikes, marches, and protests against the pass laws and other discriminatory legislation. In 1949 the A.N.C. Youth League, led by Oliver Tambo, Nelson Mandela, Walter Sisulu, and Anton Lembede, gained control of the organization.

In 1955 the A.N.C. joined forces with political and labor organizations representing Coloureds, Asians, and whites and issued its Freedom Charter, which calls for a nonracial democracy in South Africa.

A period of increased militancy and racial assertiveness followed. The massacre of blacks protesting the pass laws at Sharpeville in 1960 led the A.N.C. to call for nationwide work stoppages and civil disobedience. Nelson Mandela went underground and formed Umkhonto we Sizwe (Spear of the Nation), a military command that began a campaign of sabotage against the symbols of Apartheid, including government offices and police stations.

Mandela, who was sentenced to life imprisonment in 1964, became the symbolic leader of the nationalist movement. He was released on February 11, 1990 and named effective head of the A.N.C. on March 2.

On August 7 the ANC suspended its 29-year armed struggle against white rule, although violence between followers of the A.N.C. and of Zulu chief Gatsha Buthelezi's Inkatha movement intensified.

Until 1991, when it held its first national conference inside South Africa since 1959 and elected Mandela president, the A.N.C. maintained a government-in-exile in Zambia. It had ties to the United Democratic Front (U.D.F.), a coalition of nationalists groups in existence from 1983 to 1991. In September 1991, the A.N.C, Inkatha, and the National Party signed a peace pact designed to end the violence that hampered efforts to reach a political settlement in South Africa.

In 1940 he was expelled from college for organizing a student strike. He continued his law studies by correspondence and obtained his degree from the University of South Africa in 1942. Shortly thereafter he joined the A.N.C., South Africa's longest-standing black liberation group, rising to a position of leadership by the early 1950s.

For nearly two decades, Mandela worked to unite various resistance factions and to organize antigovernment protests. Confined by the police on several occasions, Mandela in December 1956 went on trial, along with 156 others, on charges of treason. The case lasted nearly six years, and in 1961 all the defendants were acquitted. Mandela was arrested again in August 1962 and sentenced to five years in jail for inciting a strike and traveling without proper documents. Additional charges resulted in a life sentence in June 1964.

Following his release from prison, Mandela held strategy talks with other A.N.C leaders in Zambia. He also met with Palestine Liberation Organization leader Yasir Arafat in Zambia, saying that he endorsed the goals of the P.L.O. Mandela made a world tour in June, 1990; in the United States, he addressed the United Nations in New York City, met with President George Bush at the White House.

One of the most visible leaders of the movement has been Mandela's second wife, Winnie Nomzamo Mandela. The country's first black medical social worker, Winifred Nomzamo was married to Mandela in 1958, during his first trial. After her husband's imprisonment, Winnie Mandela continued to speak out against government racial policy and to solicit international support for black equality and her husband's freedom.