1 Map A. Kingdoms and Empires of Africa This interactive map illustrates the changing societal structures in Africa prior to European colonization. The extent of trade, both land and maritime, is highlighted as well as the expansive influence of Islam. Africa, for most of this period, had yet to suffer the devastating effects of the European slave trade and, towards the end of the timeline, it is possible to see the beginning of the Portuguese foothold that would eventually give rise to imperialism and the forced migration of slaves. What factors led to the growth of the African slave trade, especially after the 11th century C.E.? Did the trading routes for the slaves correspond to the long-distance trading routes of the time? If so, why do you think that was so?