The kingdom of Mali controlled the salt trade in North Africa as well as many caravan trade routes. Several great centers of Islamic learning were also established during the Kingdom of Mali. Among them were the legendary Timbuktu, Djenne and Gao. When Mansa Musa, the leader of Mali who had contributed to the extension of the empire, died, the smaller states it had conquered broke off, and the empire crumbled.
The exact origins of the Kingdom of Songhay are not clear to historians. The first of two great rulers in the Kingdom of Songhay was Sonni Ali. He came to power in 1464 and made the Songhay perhaps the most powerful state in western/central Africa at the time. Then his successor was Mohammed Askia, who came to power in 1493. He expanded the kingdom even further and set up an even more advanced and strongly centralized government. He developed a new system of laws, expanded the military and encouraged scholarship and learning.