In the early modern world, West African kingdoms and stateless societies existed side by side. Both had predominantly agricultural economies. Stateless societies revolved around a single village or group of villages without a central capital or ruler. Kings ruled over defined areas through bureaucratic hierarchies. The Sudanic empires controlled the north-south trans-Saharan trade in gold, salt, and other items. Led by predominantly Muslim rulers, these kingdoms belonged to a wider Islamic world, allowing them access to vast trade networks and some of the most advanced scholarship in the world. Still, Muslim culture affected primarily the royal and elite classes, seldom reaching the masses.

Europeans believed a wealthy (mythical) Christian monarch named Prester John ruled the Christian kingdom of Ethiopia. This fable attracted Europeans to Ethiopia, and partly explains why the Portuguese helped the Ethiopians fight off Muslim incursions. Jesuit missionaries tried to convert Ethiopians to Roman Catholicism but were fiercely resisted and expelled in 1633.

Swahili city-states on Africa’s southeastern coast possessed a Muslim and mercantile culture. The Swahili acted as middlemen in the East African–Indian Ocean trade network, which, in the late fifteenth and early sixteenth centuries, Portugal sought to conquer and control. Swahili rulers who refused to form trading alliances with the Portuguese were attacked. The Portuguese presence caused the economic decline and death of many Swahili cities.

Slavery existed across Africa before Europeans arrived. Enslaved people were treated relatively benignly in some societies but elsewhere as chattel possessions, suffering harsh and brutal treatment. European involvement in the slave trade began around 1550, when the Portuguese purchased Africans to work in Brazil. The Dutch East India Company used enslaved Africans and southeast Asians in their Cape Colony. African entrepreneurs and merchants partnered in the trade, capturing people in the interior and exchanging them for firearms, liquor, and other goods with European slave ships. Though some kingdoms experienced a temporary rise of wealth and power, over time the slave trade was largely destabilizing. The individual suffering and social disruption in Africa caused by the enslavement of millions of Africans is impossible to estimate.