Always, since the Crusades, Europe had been conscious of Asia as a land of marvels and of wealth. Commercial relations between the Mediterranean world and the Orient were of very long standing, though subject to many vicissitudes and at times to almost complete breakdown. Roman publicists, notably the elder Pliny, deplored the drain of precious metals to the East in exchange for effete luxuries—silks, spices, perfumes—and in Graeco-Roman times there was an active maritime trade via the Red Sea to the littorals of the Arabian Sea. This is attested not only by the ‘manual for navigators and traders’^[57] known as the Periplus of the Erythrean Sea but also by the discovery near Pondicherry of a depot for the return trade from the Mediterranean—to judge from the large numbers of amphorae, largely in wine.^[58] Alexandria was the main entrepôt for sea trade, Antioch for the overland traffic, mainly in silks from China. Later, Byzantium monopolised a smaller trade, but while the smuggling of silkworm eggs in Justinian's time reduced Europe's dependence on Chinese silk, spices remained an Asian monopoly.

While the early expansion of Islam from Antioch to the Maghreb (Morocco) may not have had the catastrophic and catalytic results ascribed to it by Henri- 14 -Pirenne in Mediaeval Cities, there was undoubtedly a very marked decline in commercial contacts, more especially in the western Mediterranean. The consolidation of Muslim power had an ambivalent effect: on the one hand the Crusades brought the Franks of the West into direct contact with the Levant and increased the demand for oriental luxury goods; on the other, it effectively debarred the West from direct communication with lands eastwards from the narrow littoral of the Crusader kingdoms. Until the thirteenth century, European ideas of Asia beyond Euphrates were vague and distorted in the extreme, far below the level of knowledge in the Graeco-Roman world.

A new opening to the East came in the aftermath of the Mongol invasions; after their great reflux from the borders of the Holy Roman Empire to their ancestral steppes, the image of the Mongols in European eyes changed, in remarkably short order, from that of devilish blood-drinking monsters to one of civilised potential allies against the nearer threat of the Seljuk Turks. Between 1245 and 1253 four missions, diplomatic and evangelical, were sent to the Court of the Great Khan.^[59] Not much success accrued to their primary aims: the heretical Nestorian Christians were well established in the East, and that mighty Christian potentate Prester John proved singularly elusive. But these emissaries, highly literate and conscientious reporters, brought back a good deal of useful information as well as agreeable fantasy, and Trade soon followed the Cross. After the Polos a whole new world was opened to the traders of Venice and Genoa, the latter working from their advanced bases in the Crimea. For about a century from 1250, the ‘Mongol peace’ of Kublai Khan and his successors maintained firm order over the vast area from the Volga to Cathay, and when Pegolotti wrote his handbook, about 1340, the long caravan routes were still safe ‘by day or night’, and probably a good deal safer than many a King's Highway in Europe. Later in the fourteenth century, however, the huge but insubstantial empire broke up, and Asia entered upon a period of turbulence symbolised by the daemonic figure of Timur Lenk, Tamburlaine the Great. But at their height Italy's trade relations stretched from Norway to China, though her role was essentially a middleman's; very little of the traffic east of the Levant was directly in Italian hands, despite the presence of Genoese merchants in India and China.

Silk and spices were the great staples of the trade, though of course there were other high-value low-bulk lines—luxuries such as gems, dyes, drugs, fine brocaded fabrics. Chinese and Persian silks had a higher reputation than those produced in Europe; the trade in these seems to have been mostly overland and largely in Genoese hands. Given the monotony of foodstuffs available in Europe, the necessity of preserving the flesh of animals slaughtered for want of winter feed, and the badness of the wine (which often needed doctoring to be drinkable), spices might well be considered a necessity of life for people above the bare subsistence level of the peasantry; pepper especially was needed in large quantities for the winter ‘salting’ of meat. Venice was the great mart for spices, bought mostly in Alexandria from Muslim merchants. But in the fifteenth- 15 -century these great trades were increasingly shackled by political obstacles; not only disruptions of stability on the overland routes, but obstruction at the Levantine and Byzantine outlets into the Mediterranean.

Instability in Asia; the rise of a new Turkish power under the Osmanlis, tougher and more efficient than their Seljuk predecessors; the devastating incursions of Tamburlaine—all these imposed severe economic strains on the older states of southwest Asia such as Persia and Egypt. Twenty-five years before the fall of Constantinople, the Soldan of Egypt ‘nationalised’ pepper exports, raising the Alexandria price by over 60 per cent; a Venetian attempt at a boycott in 1480 failed before threats of violence.^[60] Byzantium had been for so long islanded by Ottoman power that its fall in 1453 merely set the seal on a virtually accomplished fact; despite the long warning, the psychological shock to Christendom was great, but not great enough to impose a decent a unity. Economically, it meant the end of the special commercial privileges held at Byzantium by Venetians and Genoese, and for the latter (compromised by their gallant part in the last days of the Christian city) the loss of their Black Sea colonies: Caffa, the modern Feodosiya, fell to the Turks in 1475. Moreover, before the marked rise in European silver production which began about 1450, output of precious metals in Europe was declining,^[61] while clearly both Egypt and Turkey were screwing up the terms of trade. Venice was thus in the paradoxical position of holding a monopoly squeezed at both ends, by ruthless price maximising by the suppliers and by an inelastic purchasing power of the customers. Yet by this time Asian luxuries were necessaries to Europe—necessary at least to the expected standard of living of her ruling classes.

The room for manoeuvre within the established trading system was thus narrow, and to all appearance narrowing; the room for manoeuvre by outflanking the established routes was limitless, or at least limited only by ignorance and fear of the unknown. For by now western Europe had the technological and organisational capacities to break out of the circle, and an increasing need to do so. The tools were to hand, and it needed only courage and imagination to accomplish this truly revolutionary task.