サハラ交易
The major power in the region in the 17th and 18th centuries had been the Bornu Empire. However, revolutions and the rise of new powers decreased the power of the Bornu empire and by 1759 its rulers had lost control over the oasis town of Bilma and access to the Trans-Saharan trade. Vassal cities of the empire gradually became autonomous, and the result by 1780 was a political array of independent states in the region.