The 1913 Native Land Act created reserves in which South Africa’s black population was supposed to reside. The reserves comprised 7% of South Africa, leaving the other 93% for white ownership. Black people could live outside the reserves only if they could prove that they were in white employment.
The reserves were defined along tribal lines – all the Zulus were supposed to live in Zululand, all the Xhosa in Transkei and Ciskei, all the Tswana in Bophuthatswana, and so on, for each of South Africa’s major language groups.
Crowding so many people into such tiny area of the land inevitably resulted in overgrazing and soil erosion, and high levels of poverty and unemployment. This made it easier for the mines to recruit migrant labour, since there was little hope of making a living in the reserves.