Answer:
The historical antecedent of the war dates back to the time when the British formally formalized the southern African annex. The British expansion in the south of the African continent had three main catalysts.
The first was the desire of the United Kingdom to gain a greater control of the trade routes that were heading towards the Indies. This was allowed by the control of the Cape (what today is, in large part, South Africa) in this region.
The second was the discovery of a mine rich in diamonds that was in the territory that connected the British Cape colony, the Orange Free State (an independent Boer colony) and the Republic of South Africa.
This republic was not the current country of South Africa, but a Boer republic established in the area. The British knew it like the Transvaal, because the territory that occupied this nation is crossed by the Vaal river.
The third reason was framed in the context of European rivalries to conquer territory. The British wanted to expand their dominance of the African continent to own more territory than the other powers that already had areas dominated in Africa, such as France and Holland.
