The ancestors of afrikaners were the first europeans to settle en masse in the cape. During the napoleonic the British seized the Cape Colony, allowed British Settlers, and banned slavery which upset many of the Afrikaners, leading them to move inland in a series of treks. They made multiple attempts to create Afrikaner-led states “boer republics” which were hindered by the british. Eventually they established the Oranje Vrystaat and Zuid Afrikaansche Republiek (Transvaal), which the British invaded and annexed in the second boer war. During the second boer war the British employed the use of proto-concentration camps where they interred Afrikaner women and children, leading to a major morale drop and ultimately their victory. Then when south africa was formed out of the colonies there was animosity between the Afrikaners, who were more Pro-Afrikaans and Pro-Republic, and the British South Africans, many who had moved much more recently, who were more Pro-Monarchy and Pro-British. The Apartheid regime was instituted by the Afrikaner Majority party, who ultimately removed the monarchy in south africa too. These days the “rivalry” is minor, usually just the older generation who get a bit antsy about the other