The Union of South Africa was a unitary state, rather than a federation like Canada and Australia, with each colony's parliaments being abolished and replaced with provincial councils.

[7] Parliamentary sovereignty was a convention of the constitution, inherited from the United Kingdom; save for procedural safeguards in respect of the entrenched sections of franchise and language, the courts were unable to intervene in Parliament's decisions.

It removed what remaining authority Whitehall had to legislate for South Africa, as well as any nominal role that the United Kingdom had in granting Royal Assent.

The monarch was represented in South Africa by a governor-general, while effective power was exercised by the Executive Council, headed by the prime minister.

[14] Louis Botha, formerly a Boer general, was appointed first prime minister of the Union, heading a coalition representing the white Afrikaner and English-speaking British diaspora communities.

[18][19] The Cape Prime Minister at the time, John X. Merriman, fought hard, but ultimately unsuccessfully, to extend this system of multi-racial franchise to the rest of South Africa.

[20] Several previous unsuccessful attempts to unite the colonies were made, with proposed political models ranging from unitary, to loosely federal.

Sir George Grey, the Governor of Cape Colony from 1854 to 1861, decided that unifying the states of southern Africa would be mutually beneficial.

[22] The Confederation model was also seen as unsuitable for the disparate entities of southern Africa, with their wildly different sizes, economies and political systems.

[23] The Molteno Unification Plan (1877), put forward by the Cape government as a more feasible unitary alternative to confederation, largely anticipated the final act of Union in 1909.

[25] Lord Carnarvon rejected the (more informed) local plans for unification, as he wished to have the process brought to a conclusion before the end of his tenure and, having little experience of southern Africa, he preferred to enforce the more familiar model of confederation used in Canada.

The British government, interested in profiting from the gold and diamond mines there and highly protective of its own citizens, demanded reforms, which the Afrikaners rejected.

British Prime Minister Lord Salisbury and members of his cabinet, in particular Colonial Secretary Joseph Chamberlain, ignored repeated warnings that Boer forces were more powerful than previous reports had suggested.

In the last months of 1899, Boer forces launched the first attacks of the war, besieging the British-held settlements of Ladysmith, Kimberley and Mafeking, and winning several engagements against British troops at Colenso, Magersfontein and Stormberg.

Numerous Boer soldiers refused to surrender and took to the countryside to carry out guerrilla operations against the British, who responded by implementing scorched earth tactics.

Using these tactics combined with a system of blockhouses and barriers to seal off Boer holdouts, the British were able to gradually track down and defeat the guerillas.

The referendum resulted from the fact that by 1920 British South Africa Company rule in Southern Rhodesia was no longer practical with many favouring some form of 'responsible government'.

Politician Sir Charles Coghlan claimed that such membership with the Union would make Southern Rhodesia the "Ulster of South Africa".

[33] Prior to the referendum, representatives of Southern Rhodesia visited Cape Town where the Prime Minister of South Africa, Jan Smuts, eventually offered terms he considered reasonable and which the United Kingdom government found acceptable.

Accession to the Cape Colony, a self-governing state with a system of multi-racial franchise and legal protection for traditional land rights, was at the time considered marginally preferable to annexation by either the Kingdom of Portugal or the German Empire.

This invitation was in turn rejected by the Union, which subsequently did not modify the administration of South West Africa and continued to adhere to the original mandate.

In 1921, Walvis Bay was integrated with the Class C Mandate over South West Africa for the rest of the Union's duration and for part of the republican era.

The Statute of Westminster passed by the British Parliament in December 1931, which repealed the Colonial Laws Validity Act and implemented the Balfour Declaration 1926, had a profound impact on the constitutional structure and status of the Union.