Similarly, in the Swahili coast, Islam made its way inland - spreading at the expense of traditional African religions.
Copper coins found at Kilwa Kisiwani appear to be of the same pure ore found on the Swahili coast.
Other works in written form are abundant, namely in north Africa, the Sahel regions of west Africa and on the Swahili coast.
Arab traders have long operated in Southeast Asia and along the East Africa's Swahili coast.
Islam was practised on the Swahili coast as early as the eighth or ninth century CE.
Arab geographers referred to the Swahili coast as the land of the zanj (blacks).
On a mission to economically control and Christianize the Swahili coast, the Portuguese attacked Kilwa first in 1505 and other cities later.
By the late 17th century, Portuguese authority on the Swahili coast began to diminish.
The Swahili coast eventually became part of the Sultanate of Oman.
They came into direct trade conflict and competition with Portuguese and other Europeans along the Swahili coast.