Trans-Saharan Africa in World HistoryDuring the heyday of camel caravan traffic from the eighth century CE arrival of Islam in North Africa to the early twentieth century building of European colonial railroads that linked the Sudan with the Atlantic the Sahara was one of the world's great commercial highways, bringing gold, slaves, and other commodities northward and sending both manufactured goods and Mediterranean culture southward into the Sudan. Historian Ralph A. Austen here tells