Britain acquired the Cape of Good Hope Colony at the southern tip of Africa in 1815 and annexed the adjacent coastal region of Natal in 1843.
Self-governing colony status was established in both in the 1850s, but not responsible government whereby a ruling government would be in place with accountable elected Ministers - as the region was still politically volatile.
Competition and conflict
Throughout the 19th century British settlers were outnumbered by both Africans and the descendants of the original Dutch settlers of the 17th century, known as Boers (farmers).
In the 1830s the latter established two independent republics in Transvaal and the Orange Free State, which Britain was forced to recognise in the early 1850s.
Conflict between the Boers and the British was constant throughout the century. There were two major wars between 1880 and 1881 and 1899 and 1902, both caused by British attempts to annex Boer territory.
Second Boer War
The second Boer War started very badly for the British and revealed the limits of British military might in its extended empire. But eventually the superior numbers of the British Army wore the Boers down.
Under the 1902 Treaty of Vereeniging the Boers agreed to surrender their two republics - Transvaal and the Orange Free State. The British Crown agreed to their request that the extension of the vote to Africans in the republics would not be decided until after the re-introduction of self-government.
Britain had long been encouraging a union of the four South African colonies. In 1908 white delegates sent a draft proposal for union to the British Parliament, which hurried through the South Africa Union Bill in 1909.
This provided for a unitary state for the four colonies of the Cape, Natal, Orange Free State, and Transvaal, rather than federation. It also excluded indigenous Africans living in the territories from all aspects of political life.
The Union of South Africa formally came into being in 1910, becoming a member of the Commonwealth in 1931, leaving in 1961, but rejoining in 1994 after the end of apartheid.