In 1910, Cape Colony, Natal, Transvaal and the Orange Free State were combined into the Union of South Africa. Unlike Canada and Australia, the Union was a unitary state, rather than a federation, with each colony's parliaments being abolished and replaced with provincial councils.
It was created partially as a way of reconciling the English and Boer settlers who had so recently been involved in the devastating Boer War. The successful, if expensive, war also finally brought about the conditions that would allow a union of the disparate colonies. In the nineteenth centuries a combination of Boer and British enmity and large African polities had made a unification too difficult to contemplate. Those problems no longer existed. Boer recalcitrance had been subdued and African tribal power had been reduced or isolated into the kingdoms of Basutoland, Swaziland and Bechuanaland.
The Union of South Africa was devised by white politicians. Africans were not consulted in any way. Previously, many of their rights had actually been defended by the British Parliament in London which respected treaties and rights of private property. Now, that power was about to be handed over to politicians and settlers in South Africa who saw the Africans as rivals or as little more than units of labour and very often sitting on land that they would like to possess. Africans rights to vote, to own land and even freedom to work were about to be assaulted by the provincial concerns of the local white population who deliberately took denied them a political voice.
This was demonstrated in 1913 with the Native Land Act. This denied Africans the right to own land on 87 percent of the Union's land area. The remaining 13 percent was of marginal, poor quality scrub with little access to fresh water or port facilities. These reserves could not support the African population. This pushed more of the Africans into the labour market as marginal migrant workers. In time, successive pass laws and stern employment regulations would further push wages down especially for the unskilled. The white settler parliament defined whites as automatically skilled. Besides, the white population was the only one given a decent education. The circle of discrimination was emplaced. The animosity between the Boers and the British was solved by combining to crush the rights of the black African. By trying to appease one recalcitrant community, the British government had accidentally victimised another, far larger, community.
The Union of South Africa loyally followed Britain into World War One. Indeed she played a crucial role in fighting and capturing the German colonies in Africa. South West Africa would be awarded as a League of Nations mandate to South Africa in 1920. In fact the idea for mandates was actually proposed by the remarkable South African statesman Jan Smuts. He had fought against the British in the Boer War but would then rise up the South African Army ranks to become one of the most influential soldiers in the British Empire.
In 1931, the statute of Westminster granted the remaining vestiges of government to all the dominion powers. This mainly gave them full responsibility for their own defence and foreign affairs which had previously been reserved to Westminster. South Africa was to all intents and purposes an independent country with just the proviso that the King (or his representative) as the head of government and would sign all laws into being.
However, South Africa's loyalty was not so clear cut by the outbreak of World War Two. Elements of the Boer population were sympathetic to the Nazi views on race. Particularly as they thought the British were 'going soft' on the native question in other African colonies further North. In the end it was only by a razor thin majority that the South African government agreed to declare war and support Britain.
The predominantly Boer backed Nationalist Party was to win the 1948 election, again by the slimmest of majorities. But it would now use all the powers delegated to it from Westminster to withdraw from the British Empire in 1961 and set up a fully segregated apartheid regime. The attempt to placate and draw the Boers into the Empire had ended in failure. Although the main victims of this failure was not the British settlers or government but the Africans who found themselves living under this odious regime.