The Union of South Africa (South Africa)
The Union of South Africa is the historical predecessor to the present-day Republic of South Africa. It came into being on 31 May 1910 with the unification of the Cape Colony, the Natal Colony, the Transvaal, and the Orange River Colony. It included the territories that were formerly a part of the South African Republic and the Orange Free State.
Following the First World War, the Union of South Africa was a signatory of the Treaty of Versailles and became one of the founding members of the League of Nations. It was conferred the administration of South West Africa (now known as Namibia) as a League of Nations mandate. It became treated in most respects as another province of the Union, but it never was formally annexed.
Like Canada and Australia, the Union of South Africa was a self-governing dominion of the British Empire. The Union came to an end with the enactment of the constitution of 1961, by which it became a republic and temporarily left the Commonwealth.