The combined land areas of Africa, Europe, and Asia embrace within their perimeters the Mediterranean, Black, Caspian, Aral, China, Arabian, Red, Baltic, and North seas: altogether their area was historically thought of only as a flat Universe sandwiched between heaven above and hell below and seemingly stretching away to infinity in all lateral directions. Yet the total land area of this flat world constitutes less than 17 percent of the subsequently-discovered-to-be-spherical Planet Earth’s surface. All the great empires of written history before A.D. 1500 lay well within that “known” flat world: it was and as yet remains the spontaneous theater of popular historical conceptioning.