It was fought between the British Empire and the Boers (aka Afrikaners) of the Transvaal and Orange Free State.

The Boers had always resented the Anglicization of (British held) South Africa, and Britain's antislavery policies. From 1833 the Boers had migrated away from South Africa and into the African tribal lands. There they set up the republics of the Transvaal and the Orange Free State.

Diamonds and gold were found in these new regions, which led to conflict between the Boers and Britain over the find.

Skirmishes between the two sides began as early as 1890. Britain won military control of the main cities and annexed all the land. But the Boer's fought back with a guerrilla campaign. The British army countered by searching and arresting those guerilla units they could find, holding them, and their families, in concentration camps.

The war ended with the signing of the Peace of Vereeniging, on May 31, 1902. The British Empire prevailed, annexing both the Transvaal and the Orange Free State which would later become provinces of South Africa.