Empires

The development of the region's economy allowed more centralized states and civilizations to form, beginning with the Nok civilization which began 500 B.C. and the Ghana Empire in the 8 th century AD which stretched to the Mali empire . Based on the city of Kumbi Saleh in modern-day Mauritania, the empire came to dominate much of the region until its defeat by Almoravid invaders in 1052. The Sosso Empire sought to fill the void, but was defeated (c. 1240) by the Mandinka forces of Sundiata Keita , founder of the new Mali Empire . The Mali Empire continued to flourish for several centuries, most particularly under Sundiata's grandnephew) Musa I , before a succession of weak rulers led to its collapse under Mossi , Tuareg and Songhai invaders. In the fifteenth century, the Songhai would form a new dominant state based on Gao , in the Songhai Empire , under the leadership of Sonni Ali and Askia Mohammed . Further south, Osei Tutu and Okomfo Anokye have started to build the Empire of Ashanti Meanwhile, south of the Sudan, strong city states arose in Igboland , such as the Kingdom of Nri in the tenth century, while Ife , Bono , and Benin arose around the fourteenth century. Further east, Oyo arose as the dominant Yoruba state and the Aro Confederacy as a dominant Igbo state in modern-day Nigeria. Slavery and European contact