The Penguin History of the World

For goods in quantity, water transport was already likely to be cheaper and simpler than transport by land; this was to be a constant of economic life until the coming of the steam railway. Long before caravans began to bring up to Mesopotamia and Egypt the gums and resins of the south Arabian coasts, ships were carrying them up the Red Sea and merchants were moving back and forth in trading vessels across the Aegean. Understandably, it was in maritime technology that some of the most important advances in transport were made.

We know that Neolithic peoples could make long journeys by sea in dugout canoes and there is some evidence of navigation from the seventh millennium BC. The Egyptians of the Third Dynasty had put a sail on a sea-going ship; the central mast and square sail were the beginning of seamanship relying on anything but human energy. Improvements of rigging came slowly over the next two millennia. It has been thought that these made some approach to the fore-and-aft rigging which was necessary if ships were to sail closer to the wind, but for the most part the ships of antiquity were square-rigged. Because of this, the direction of prevailing winds was decisive in setting patterns of sea-borne communication. The only other source of energy was human: the invention of the oar is an early one and it provided the motive power for long sea crossings as well as for close handling. It seems likely, though, that oars were used more frequently in warships, and sail in what it is at a very early date possible to call merchantmen. By the thirteenth century BC, ships capable of carrying more than 200 copper ingots were sailing about the eastern Mediterranean, and within a few centuries more, some of these ships were being fitted with watertight decks.

Even in recent times goods have been exchanged or bartered and no doubt this was what trade meant for most of antiquity. Yet a great step was taken when money was invented. This seems to have happened in Mesopotamia, where values of account were being given in measures of grain or silver before 2000 BC. Copper ingots seem to have been treated as monetary units throughout the Mediterranean in the late Bronze Age. The first officially sealed means of exchange which survives comes from Cappadocia in the form of ingots of silver of the late third millennium BC: this was a true metal currency. Yet although money is an important invention and one which was to spread, we have to wait until the eighth century BC for the Assyrians to have a silver standard for the first coins. Refined monetary devices (and Mesopotamia had a credit system and bills of exchange in early times) may help to promote trade, but they are not indispensable. Peoples in the ancient world could get along without them. The Phoenicians, a trading people of legendary skill and acumen, did not have a currency until the sixth century BC; Egypt, a centrally controlled economy and of impressive wealth, did not adopt a coinage until two centuries after that, and Celtic Europe, for all its trade in metal goods, did not coin money until two centuries later still.

As for economic exchange between communities, confident generalization about its earliest stages is even more hazardous. Once into the era of historical record, we can see many activities going on which involve the transfer of commodities, not all of them aimed at monetary gain. Payment of tribute, symbolic or diplomatic gifts between rulers and votive offerings were some of the forms it took. We should not rush to be over-definite; right down to the nineteenth century AD the Chinese empire conceived its foreign trade in terms of tribute from the outside world, and the Pharaohs had a way of translating trade with the Aegean into similar notions to judge by tomb-paintings. In the ancient world, such transactions might include the transfer of standard objects such as tripods or vessels of a certain weight or rings of uniform size which therefore present at an early date some of the characteristics of currency. Sometimes such things were useful; sometimes they were merely tokens. All that is wholly certain is that the movement of commodities increased and that much of this increase in the end took the form of the profitable exchanges we now think of as commerce.