The development of the region's economy allowed more centralized states to form, beginning with the Ghana Empire. The empire was founded in the eighth century by Soninke, a Mandé peoples who lived at the crossroads of this new trade, around the city of Kumbi Saleh. After 800, the empire expanded rapidly, coming to dominate the entire western Sudan; at its height, the empire could field an army of 200,000 soldiers. In the tenth century, however, Islam was steadily growing in the region, and in 1052 the Almoravids launched a jihad against the empire, sacking Kumbi Saleh.

The first successor to the Ghana Empire was that of the Sosso, a Takrur people who built their empire on the ruins of the old. Despite initial successes, however, the Sosso king Soumaoro Kanté was defeated by the Mandinka prince Sundiata Keita at the Battle of Kirina in 1240, toppling the Sosso and guaranteeing the supremacy of Sundiata's new Mali Empire.

Under Sundiata's successors, most notably his son Wali Keita (r. c. 1255-1270) and his grand-nephew Kankan Musa I (r. c. 1312-1337), the Mali Empire continued to expand, eventually creating a centralized state including most of West Africa. Trade flourished, while Kankan Musa I founded a university at Timbuktu and instituted a program of free health care and education for Malian citizens with the help of doctors and scholars brought back from his legendary hajj.

Kankan Musa's successors, however, weakened the empire significantly, leading the city-state of Gao to make a bid for independence and regional power in the fifteenth century. Under the leadership of Sunni Ali (r. 1464-1492), the Songhai of Gao formed the Songhai Empire, which would fill the vacuum left by the Mali Empire's collapse. By the end of the century, the Songhai Empire was the dominant force in the region, and through the leadership of Askia Mohammad (c. 1442-1538)), underwent a revival in trade, education, and Islamic religion. A civil war over succession greatly weakened the empire, however, leading to a 1591 invasion by Moroccan Sultan Ahmed el-Mansour that sacked Gao and crippled the empire.

Meanwhile, south of the Sudan, strong city states arose in Ife, Bono, and Benin around the fourteenth and fifteenth centuries. Further east, Oyo arose as the dominant Yoruba state and the Aro Confederacy around the 18th and 19th centuries in the Far East in modern-day Nigeria.