For centuries, land and livestock sustained African livelihood and people rarely worked for a wage.
In late 19th century, Europeans were attracted to Africa due to its vast resources of land and minerals.
They came to Africa hoping to establish plantations and mines to produce crops and minerals for export to Europe. But there was an unexpected problem-shortage of labour. No one was willing to work for wages, so they adopted various methods to get people to work.
Then the rinderpest or the deadly disease of cattle plague arrived in Africa through infected British cattle imported to Africa and the infectious disease killed 90% of the African cattle.
The loss of cattle destroyed African livelihood. Planters, mine owners and colonial governments now successfully monopolised their power and forced Africans to work for wages. Control over scarce cattle resource enabled European colonisers to conquer and subdue Africa.