Postage stamps and postal history of Stellaland Republic
Stellaland was a short-lived Boer republic from 1882 until 1885, located in southern Bechuanaland, west of the then South African Republic, with Vryburg as its capital. It was incorporated in British Bechuanaland in 1885.
Source: Wikipedia — Postage stamps and postal history of Stellaland Republic (CC BY-SA 4.0)