_THE EXPANSION OF REGIONAL KNOWLEDGE_ We have seen what the geographers of antiquity thought about the general distribution of land and water and about the physical processes of the earth’s surface. We now must study a subject which is less concerned with what they thought than with what they actually knew—however vague and inexact this knowledge was. Though the heritage of knowledge which antiquity left to the Middle Ages of the countries and regions of the _oikoumene_ was vast, much had been lost and much garbled in the process of transmission. Hence it would be beside the point to discuss the details of topographic information contained in the works of Strabo, Pliny, and Ptolemy; our aim is merely to indicate in a broad way the limits of the regional knowledge of the ancient world. This can best be done by sketching the various stages in which the horizon of geography was expanded until it reached the Shetlands and Scandinavia in the north, China in the east, and, perhaps, the Central African mountains in the south. EXPANSION OF GREEK REGIONAL KNOWLEDGE Homer’s geographical horizon was limited by the Mediterranean—one might almost say Aegean—shores; Italy, Sicily, and everything to the west was a realm of fable, and his acquaintance with the Black Sea coasts was little better. The colonizing movement of the eighth to the sixth centuries before Christ brought Greek settlers to these coasts; and through them there was gained some acquaintance with the country behind them, which found expression in the writings of Hecataeus at the close of the sixth century. With this writer ancient geography begins to assume its familiar classical form. He shows some slight knowledge of Central Asia beyond the Caspian Sea and is even aware of the existence of India—or at least of the northwestern portions of that peninsula. The great struggle with Persia brought the Greeks into much closer relations with Asia, and a corresponding increase in geographical knowledge ensued. This was summed up by Herodotus. Much of his geography is fabulous and legendary, but much of it is of surprising detail and accuracy. The voyage of Scylax of Caryanda from the Indus to the Persian Gulf had brought the Indian Ocean within Greek ken. Herodotus also describes the rivers of Scythia and of Central Asia and displays detailed familiarity with Egypt and northeastern Africa; he knew less of the West, although at about this same time the voyages of the Carthaginian Hanno in the Atlantic Ocean extended the horizon at least as far as the Canaries, which were destined to remain on the limits of the known world in that direction for many centuries to come. Shortly after Herodotus, Ctesias, who had lived seventeen years at the Persian court, wrote his _Persica_ and _Indica_, in which we find collected together many of the fabulous and marvelous tales of Oriental animals and monsters which were later to figure so strikingly in the _Historia