The Second Boer War (11 October 1899 – 31 May 1902) was fought between the British Empire and two Boer states, the South African Republic (Republic of Transvaal) and the Orange Free State, over the Empire's influence in South Africa. It is also known variously as the Boer War, Anglo-Boer War, or South African War. Initial Boer attacks were successful, and although British reinforcements later reversed these, the war continued for years with Boer guerrilla warfare, until harsh British counter-measures brought the Boers to terms.