The Spanish and Portuguese arrival ended the isolation of the New World from other societies. After 1500, millions of Europeans and Africans settled in the Americas. Biological and ecological exchange—called the Columbian Exchange—changed the character of both new and old societies. Old World diseases decimated New World populations.
From top: From Aden, at the farthest western reach of the Indian Ocean and one of the richest emporia of its time, He sailed down the east coast of Africa. Among his ports of call was Mombasa (center), known for exports of gold & iron. He traveled as far south as Kilwa, still well north of Sofala, the most distant Arab port on the coast (lower). The progression from Aden’s cosmopolitan bustle to Sofala’s isolation is easily seen in these colored engravings from the late 16th century.