The Periplus Maris Erythraei , "Circumnavigation of the Red Sea," is the single most important source of information for ancient Rome's maritime trade in these waters (i.e., the Red Sea, Gulf of Aden, and western Indian Ocean). Written in the first century A.D. by a Greek merchant or skipper, it is a short manual for the traders who sailed from the Red Sea ports of Roman Egypt to buy and sell in the various ports along the coast of eastern Africa,...