Kilwa Kisiwani Island, which lies in southern Tanzania and is easily accessible by boat from the mainland, was formerly a bustling harbor. Oman Sultans and Persian traders were the first to live there from the ninth to the nineteenth centuries. 

Then, starting in the eleventh century, the Kilwa sultans benefited financially from their dominance over the gold trade. In the past, it served as the Kilwa Sultanate's capital. This was a medieval sultanate, and the 13th through the 15th century saw the height of its power. It covered the whole area along the Swahili Coast.