Book excerpt: From the birth of Islam in the seventh century to the voyages of European exploration in the fifteenth, Africa was at the center of a vibrant exchange of goods and ideas. It was an African golden age in which places like Ghana, Nubia, and Zimbabwe became the crossroads of civilizations, and where African royals, thinkers, and artists played celebrated roles in the globalized world of the Middle Ages. Drawing on fragmented written sources as well as his many years of experience as an archaeologist, the author reconstructs an African past that is too often denied its place in history. He looks at ruined cities found in the mangrove, exquisite pieces of art, rare artifacts like the golden rhinoceros of Mapungubwe, ancient maps, and accounts left by geographers and travelers