Union ya Aforika Borwa e na ya tlhangwa ka ngwaga wa 1910 ka go kopantsha dikoloni tse nne tsa Brithani: Cape Colony, Natal Colony, Transvaal Colony, le Orange River Colony. Transvaal Colony le Orange River Colony e ne ele diriphabuliki tse di ikemetseng pele ga Boer War ya Bobedi, di bitswa South African Republic le Orange Free State. Dikoloni tse nne tse, e ne ya nna tsona di profense tsa mathomo tsa Union: Cape Province, Transvaal Province, Natal Province, Orange Free State Province.