Medieval West Africa
By 800 AD, the people of Djenne-Djeno had built a tall wall of mud-bricks around their town, to protect themselves from their enemies. They wore gold jewelry. On the other end of the Niger river, in the forests down near the Atlantic Ocean in modern Nigeria, the people of Igbo-Ukwu were smelting copper and tin into bronze by 900 AD. They weren't using the same methods as in North Africa, so they seem to have invented bronze for themselves. They made sculptures with it using a lost-wax method (but again, not the same lost-wax method as in North Africa at this time).
A tour of Timbuktu
Around the same time in nearby Ife, Yoruba people were also building cities. Their Oni (kings) were thought to be descended from the creator god Oduduwa, whose worship centered on the small city of Ife. They, too, produced bronze statues.
Soon after that, though, Islamic traders and soldiers began to cross the Sahara desert from North Africa and attack Djenne-Djeno. Possibly they were driven by increasing droughts associated with the Medieval Warming Period.
By 1000 AD, Djenne-Djeno was less powerful than before, and by 1400 AD, nobody lived there anymore. They had all moved to a new, Islamic town called Djenne. The Yoruba people, further away from the Sahara and the Islamic invaders, seem to have lasted longer, and to have still been doing pretty well when the first Portuguese explorers arrived from Europe near the end of the 1400s AD.
Ancient West African Kingdoms: Ghana, Mali, and Songhai (Understanding People in the Past) by Mary Quigley (2002).1403400989
The Royal Kingdoms of Ghana, Mali and Songhay: Life in Medieval Africa by Patricia and Frederick McKissack (1995) 0805042598
Mali Songhay: The Western Sudan (African Kingdoms of the Past)
by Kenny Mann (1996) - highly recommended by teachers.0875186564
East African history
North African history