The Sand River Convention was a convention whereby Great Britain formally recognised the independence of the Transvaal Boer republic that had been established beyond the Vaal River. In return, the Boers promised that slavery would be outlawed in the Transvaal and that they would not interfere in the Orange River Sovereignty's affairs. The convention was signed on 17 January 1852 by Andries Pretorius (for the Boers) and William Hogge and Mostyn Owen (for Great Britain) in a marquee on the banks of the Sand River near Ventersburg.
One of the causes of the First Boer War was the breach by the British of this convention on 12 April 1877.
Coordinates: 28°13′55″S 27°05′21″E / 28.23194°S 27.08917°E