In 1386, when this naive plaint was addressed to Richard II by the dispossessed King of Armenia, conditions in Asia, even more than those in Europe, were such as to make the plans of Sanuto forever impossible. Johan Schiltberger, journeying to the Orient early in the fifteenth century, encountered dangers and difficulties unknown to Marco Polo a hundred years earlier. The successors of Kublai Khan no longer ruled in China; while the Ilkhans of Persia, having long since adopted Mohammedanism, were now as ill-disposed as formerly they had been friendly toward Christian states. Eastern and central Asia was indeed once more closing to Europeans: its rulers no longer sought alliance with Christian princes; no longer requested the service of papal missionaries; no longer welcomed traders and travelers. And in the Levant itself ominous changes were portending: the Ottoman Turks, pressing upon the Greek Empire from Asia Minor and the Balkan Peninsula, were already well advanced upon their career of blighting conquest which was destined to throw Christendom upon the defensive for more than two centuries. At the opening of the fifteenth century, although the trade routes had not been closed by the Turks, the _Drang nach Osten_--the hope of cutting through the Moslem barrier in order to establish direct connection with India--was at an end. Unless a new way to the East could be found, the better part of the treasure of the Orient was lost to Europe. IV Long before the fifteenth century many men had thought it possible to reach India by sailing around Africa. Since classical times geographers had both asserted and denied the possibility. During the Middle Ages the Ptolemaic theory was in the ascendant; but the observations of thirteenth-century travelers gave powerful support to the ideas of Eratosthenes. Europeans who had sailed from Malacca to Hormos, or had read the book of Marco Polo or Friar Oderic, knew well that no impenetrable swamp guarded the southern approaches to Asia; while those who had seen or heard of Arab ships clearing from Calicut for Aden could scarcely avoid the inference that a wider sweep to the south might have brought the same ships to Lisbon or Venice.