What is the name of the river that flows through the center of the medieval Mali and Songhai Empires?

The river that flows through the center of the medieval Mali and Songhai Empires is the Niger River. This river played a crucial role in the development and prosperity of these empires as it served as a vital waterway for trade, agriculture, and transportation. The Niger is one of the longest rivers in Africa and its basin facilitated trade routes across the Sahara Desert, connecting various regions and enabling the exchange of goods like gold, salt, and other commodities that fueled the economies of these powerful empires. In contrast, the other rivers listed, such as the Congo, Zambezi, and Limpopo, are located in different parts of Africa and did not have the same historical significance to the Mali and Songhai Empires.