Mining in South Africa was once the main driving force behind the history and development of Africa's most advanced and richest 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 gold field there, the biggest of them all.