Venice and Genoa, grown rich and powerful through trade with India and the nearer countries of the Orient, had for a space enjoyed a prosperity and revival of culture that were felt throughout Christendom. Then had come the conquest of Spain and domination of the Mediterranean by the Moors, and, afterward, the wars of the Crusades, which had checked the Saracen advance but interrupted all other commerce with the infidels. Meanwhile, as though to compensate for this loss, the great Mongolian conqueror Genghis Khan had fulfilled his remarkable destiny and, instead of adopting measures to prevent it, invited western intercourse with the countries he had brought under his sway, and China, about which almost nothing was then generally known, was visited overland by traders, adventurers, and missionaries. Marco Polo, a Venetian, after spending more than twenty years in the far east, part of the time in the service of the Great Khan Kubilay, had returned by way of India and Persia, laden with jewels of enormous value, and had written a book descriptive of the countries he had seen and the wealth and customs of the people. In the fourteenth century, when the Mongolian dynasty was overthrown, the Asiatics had again turned hostile and the land route was closed. But during this open season it had become known that Cathay was not the end of the world, as had been supposed—that there was an ocean beyond and the wonderful Island of Cipango (Japan) and other islands rich in spices and costly products; and Europe began to wonder, since the Tartars barred the route by land, whether these desirable places might not be accessible by water. “Between wondering and the attempt,” says Hawthorne, “there was a considerable interval, for the idea was too novel to be digested all at once. But it was an age of unbridled license of imagination and of desperate courage. The mere possibility of encountering perils never until then conceived of was allurement enough, as, even to-day, our young adventurers go forth to die on the ice fields of the north and south poles, or in the mysterious heart of savage Africa, or on the ghastly plateaux of Tibet. In addition, there were the fabulous rewards that success seemed to promise.”