The Anglo-Boer War was fought between Great Britain and South Africa Republic (Transvaal) and Orange Free State.
The Boers were descendants of the original Dutch settlers in South Africa. When Britain took possession of the Dutch Cape colony it sparkled resistance from the Boers. They escaped to African tribal territory and founded the Republic of Transvaal and Orange Free State, this was peaceful until the British found diamonds and gold in the region and the war started.