Mining has been the main driving force behind the history and development of Africa's most advanced economy. Large-scale and profitable mining started with the discovery of a diamond on the banks of the Orange River in 1867 by Erasmus Jacobs and the subsequent discovery and exploitation of the Kimberley pipes a few years later. Gold rushes to Pilgrim's Rest and Barberton were precursors to the biggest discovery of all, the Main Reef/Main Reef Leader on Gerhardus Oosthuizen's farm Langlaagte, Portion C, in 1886, the Witwatersrand Gold Rush and the subsequent rapid development of the goldfield there, the biggest of them all.