Arab migrations and mercantile activity along the east coast of Africa increased enormously, extending up to Malindi, Zanzibar, etc. The Arab trade included large-scale export of slaves, gold, ivory, etc.
The Arabs brought Africa more closely into the Indian Ocean & Middle Eastern trade.
The Ethiopian Kingdom
It was a powerful Kingdom having many towns. The Ethiopians were engaged in are Indian Ocean trade across Aden to India.
These Ethiopians were Christians. They were closely allied to the Byzantine Empire in the Indian Ocean trade. Their economic position weakened with the decline of d Byzantine Empire.