=144. The revolution about 1500; topics to be considered.=—The period centering about the year 1500 was marked by changes so rapid and so extensive that they deserve the name of revolution. The changes affected not only the intellectual life of Europe (the Renaissance) and its religious life (the Protestant Revolt or Reformation); they caused a revolution also in the world of politics and in the world of industry and commerce. It will be necessary to survey some of these changes before we return to the narrative of the history of commerce. Three main topics will occupy the attention: first, the extension of the commercial area by exploration and discovery; second, the development of the commercial organization by new forms of cooperation; third, the rise of modern states in Europe, and their influence on the growth of commerce. =145. Growth of geographical knowledge. Asia.=—About the year 1000, to most people in Europe “the world” meant scarcely more than the village in which they lived, so limited were their interests and their knowledge. Pilgrims to the holy places in Palestine brought back with them knowledge of this edge of Asia, but what the Greeks and Romans knew of that continent and of Africa had been forgotten, and even the better educated people thought of the outer parts of the world as mysterious regions, wrapped in darkness or peopled with prodigies, when they thought of them at all. The growth of the Levant trade and the crusades caused an increase in interest and in information. After the year 1200, when a great Mongol or Tartar Empire was established in inner Asia by Genghis Khan, Europeans began to penetrate Asia seeking aid from the Mongols against their enemies the Turks. Ambassadors, missionaries, merchants, and explorers made the journey so frequently that a regular guide-book was written by an Italian soon after 1300; and about the same time the Venetian Marco Polo returned from a long stay in China and described his travels. He had gone by land, through Persia, Turkestan, and Mongolia, and, returning by sea, he could tell also about Japan, the great Malay islands, Burmah, India, etc. Before the invention of printing knowledge spread slowly, but the maps of the fifteenth and sixteenth centuries show that the results of these explorations were not lost, and Europe had become conscious that Asia was bounded by a sea on the east. [Illustration: A MEDIEVAL MAP OF THE WORLD (The Laurentian Portolano. 1351)]