The Greeks celebrated under the name of Hippalus the pilot who first among their mariners made use of the seasonal monsoon winds for the direct passage from the mouth of the Red Sea to the coast of India opposite instead of following the shoreline of Arabia and Baluchistan. By the second century after Christ the ocean route to southern China was vaguely known to the Greeks of Alexandria. Meanwhile the land route through the heart of Asia had penetrated to Northern China, and silk from that source was finding its way to the Mediterranean through Tyre.
Silk was a commodity typical of the then traffic by land, for the cost of animal transport was great and could only be borne by goods occupying little space in proportion to their value, such as gold, silver, precious stones, fine linen, and incense. Within the Mediterranean, however, cargoes of grain to such places as Rome constituted a beginning of sea carriage in bulk. Fragile wares such as the art pottery of Athens were transported to every shore.
The greatness of Constantinople during the early middle ages was in part based on a continuance of the land traffic through the Balkan Peninsula and Asia Minor. The Saracen and Moorish fleets had rendered the Mediterranean un safe, and piracy, which had been suppressed while the Roman empire was efficient, had again become rife. Gradually the sea traffic recovered, being organized afresh by the Italian maritime cities, and the later crusaders, in the 12th and i3th centuries, were carried eastward by the ships of Venice. The fact that at this time a single race, the Arabs, dominated the caravan tracks of the Near East and also the sea ways of the Indian Ocean undoubtedly favoured the development of the trade with the Middle and Far East, although Christendom was excluded from the Eastern seas and had to buy silks and spices of the Muslims at Alexandria and Aleppo. Thus the principal trade of the world in the Middle Ages came to be conducted in two separate compartments, Eastern and Western; the goods went through, but not the men.
In Europe the Italian cities, especially Venice and Genoa, un dertook the forwarding into the West of the wares of the East. The lie of the Italian peninsula south eastward towards the Egyptian and Syrian ends of the desert routes was such as to favour sea transport along the Italian coasts into the heart of the Western world. From Northern Italy trains of pack animals car ried the goods over the Alpine passes to the Rhine, down which river they were transported in boats to Cologne and the cities of Flanders for distribution over Northern France, England, North ern Germany, and Scandinavia. On the return journey furs from
the northern forests were a principal article of traffic. Important banking houses rose to wealth in the cities of South Germany as well as in Venice by financing merchants along this trade route.
At certain times, and notably under the short-lived Mongol Empire in the 13th and 14th centuries, there were notable revivals of the traffic from the Far East through the heart of Asia, al though normally the turmoil of barbarous peoples rendered the passage unsafe and costly. The trans-continental caravan route came out either at Aleppo or at the head of the Sea of Azof. The Venetian traveller, Marco Polo, went in at Acre during the Mongol epoch and travelled safely to Cathay or Northern China. The Genoese, from Constantinople, for a couple of generations in the 14th century did a considerable trade with the East through the Black Sea.
In the 15th cen tury a change in the course of European trade took place which must have appeared even to contemporaries as of the first impor tance. Venice began to send forward the wares received from the East no longer over the Alps and by the Rhine, but by an annual fleet through the Straits of Gibraltar to Flanders, with a call of some of the ships at Southampton. The overland traffic soon yielded to the new competition, and the financial houses of the south German towns transferred themselves to the Netherlands. There had long been a local trade of English wine ships to Bordeaux and the advent of the Italian pilots, now equipped with the mariner's compass, into the outer seas with the valuable wares of the East must have stimulated ideas of bolder venture in the northern ports. The exploration of the West coast of Africa, organized from Portugal by the half-English Prince Henry the Navigator, was contemporary with, and no doubt incidental to, this development. If sea venture round the West of Europe was cutting out the continental traffic across Europe, why should not a greater venture round the South of Africa cut out the traffic across Egypt and Syria? The spices of the Orient would then reach Lon don by an unbroken voyage with only terminal handling of goods, whereas by Egypt and the Rhine there was a chain of three sea voyages, with two expensive land sections intercalated, and han dling of the goods at least six and more often eight or ten times.