Under white minority rule in the Union of South Africa, most of the senators were chosen by an electoral college consisting of members of each of the four provincial councils and Members of the House of Assembly (the lower house of Parliament, directly elected).

They were elected for a ten-year term, by the members serving during the final session of the legislatures of each of the four colonies which joined the Union of South Africa.

The remaining eight seats were filled, by appointment (also for ten-year terms) by the Governor-General-in-Council (in effect by General Louis Botha's first Union government).

Section 24 of the South Africa Act 1909 provided that, of the nominated senators, One-half of their number shall be selected on the ground mainly of their thorough acquaintance, by reason of their official experience or otherwise, with the reasonable wants and wishes of the coloured races in South Africa.Casual vacancies in the representation of the provinces, in the First Senate only, were filled by an electoral college composed of the members of the relevant Provincial Council.

After the South African general election, 1929 the Senate dissolution power was used for the first time, on 16 August 1929.

The new seats were filled by indirect election, the black electors being officeholders such as tribal chiefs and the members of local government bodies.

Just before the expiry of the ten-year Senate term, the UP split over the issue of South Africa's participation in the Second World War.

[4] After the South African general election, 1948 a Reunited National Party-Afrikaner Party coalition came to power, with minority support in the Senate.

[5] The eight nominated senators were appointed on 28 July 1948 and the Electoral Colleges met in the provincial capitals the following day.

[6] The South West Africa Affairs Amendment Act 1949, added four additional members to the Senate, of whom two were to be elected, and two nominated by the governor-general.

[10] In 1955, Nationalist prime minister Johannes Strijdom attempted to amend one of the entrenched clauses in the Constitution, to deprive Coloured people of their voting rights, but his party did not have the constitutionally required two-thirds majority in a joint session of both houses of Parliament.

It was decided to alter the composition and electoral system for the Senate, to enable the Separate Representation of Voters Act 1951 to be validated.

The number of nominated senators from the Union, went back to eight and the requirement for half of them to be acquainted with the 'reasonable wants and wishes' of non-white South Africans was abolished.

South-West Africa's representation in the South African Parliament was abolished in 1977, to pave the way for independence for the territory.

[13] In 1980, Prime Minister P.W Botha began a process of constitutional reform, with the establishment of the President's Council, a 60-seat advisory body with provision for ten Coloureds, five Indians, and one Chinese, but no black members.

[15] It was abolished under the terms of the Republic of South Africa Constitution Fifth Amendment Act with effect from 1 January 1981, which established the President's Council from the same date.