About 3300 BC, the historical record opens in Africa with the rise of literacy in the Pharaonic-ruled civilization of Ancient Egypt, which continued, with varying levels of influence over other areas, until 343 BC. Prominent civilisations at different times include Carthage, the Kingdom of Aksum, the Nubian kingdoms, the empires of the Sahel (Kanem-Bornu, Ghana, Mali, and Songhai), Great Zimbabwe, and the Kongo.
After the Sahara had become a desert it did not present an impenetrable barrier for travellers between north and south. Even prior to the introduction of the camel the use of oxen for desert crossing was common, and trade routes followed oases that were strung across the desert. The camel was first brought to Egypt by the Persians after 525 BC, although large herds did not become common enough in North Africa to establish the trans-Saharan trade until the eighth century AD. The Sanhaja Berbers were the first to exploit this.
Pre-colonial Africa possessed perhaps as many as 10,000 different states and polities characterised by different sorts of political organisation and rule. These included small family groups of hunter-gatherers such as the San people of southern Africa; larger, more structured groups such as the family clan groupings of the Bantu-speaking people of central and southern Africa and heavily-structured clan groups in the Horn of Africa, the Sahelian Kingdoms, and autonomous city-states such as the Swahili coastal trading towns of the East African coast, whose trade network extended as far as China.
In 1414, the Chinese admiral Zheng He visited Africa's east coast. In 1482, the Portuguese established the first of many trading stations along the coast of Ghana at Elmina. The chief commodities dealt in were slaves, gold, ivory and spices. The European discovery of the Americas in 1492 was followed by a great development of the slave trade, which, before the Portuguese era, had been an overland trade almost exclusively, and never confined to any one continent.
In West Africa, the decline of the Atlantic slave trade in the 1820s caused dramatic economic shifts in local polities. The gradual decline of slave-trading, prompted by a lack of demand for slaves in the New World, increasing anti-slavery legislation in Europe and America, and the British navy's increasing presence off the West African coast, obliged African states to adopt new economies. The largest powers of West Africa: the Asante Confederacy, the Kingdom of Dahomey, and the Oyo Empire, adopted different ways of adapting to the shift. Asante and Dahomey concentrated on the development of "legitimate commerce" in the form of palm oil, cocoa, timber and gold, forming the bedrock of West Africa's modern export trade. The Oyo Empire, unable to adapt, collapsed into civil wars.
