Her Majesty The Queen, about to visit Australia

[Mike_Oettle]

Just to clarify things, Peter, while the four self-governing colonies (each with its own parliament until that time) that came together in 1910 formally styled themselves the Union of South Africa, there was no doubt in the mind of the government (leaving aside the republican faction) that the country was in fact a British Dominion.
And Dominion status became even more important following the Act of Westminster, because it meant that South Africa (like Canada, Newfoundland, Australia and New Zealand) became a sovereign state equal in status to Great Britain.
Also remember that under British rule (up to 1947), India was not a Dominion. It took up that status at independence, but quickly wriggled out of it, becoming a republic within the Commonwealth in 1950. Pakistan took a bit longer, only becoming a republic in 1956.
Until 1950 the concept of a republic within the Commonwealth was unthinkable (which is why Éire ducked out on becoming a full-scale republic).
But in the mind of the apartheid government, adopting the status of a republic within the Commonwealth was too much like kow-towing. It wanted out completely, because it did not want the “Club” to tell it how to run the country.
The “Club” likewise did not want to permit apartheid South Africa to continue under its ægis.
The referendum which brought about the Republic of South Africa was in fact contrary to law, because it permitted only white people to vote (Coloured men in the Cape Province still possessed a parliamentary franchise) and it extended the franchise to white residents of South West Africa, a country which never did become part of South Africa, even though at the time it had MPs sitting in Parliament in Cape Town.
The outcome was the result of knoeierey and verneukery, and it put a question mark on South Africa’s international legitimacy for the next three decades.
While these last remarks are entirely off on a tangent, I thought I should add that even before the National Party came to power in 1948, South Africa was running contrary to international opinion: Prime Minister Jan Smuts, who had helped found the League of Nations and the United Nations (and had a key role in transforming the British Empire into the Commonwealth) was already defying the UN by telling it that it had no business in South West Africa.
Getting back on topic, I am proud of having been born a subject of King George VI, and retain my affection for and loyalty to his daughter, the first and only British sovereign to bear the title Queen of South Africa.
Regards,
Mike