The wealth of East African city-states was based on Trade.
Archaeology investigations furnish testimony that the city-states conducted on successful long-distance commerce with Persia, India, and China. Coins from these countries have been observed in several of the African city-states. Also recovered were samples of ceramics from Persia and Arabia, Chinese qing bai, and Cizhou pottery, as well as kohl stems, glass stones, bronze glasses, and something of rock crystal, follow the China trade. Other wares from Indonesia, seeing back to the 13th century, designate that Southeast Asia was also a member of the East African city-state marketing system.