Of copper, tin and iron

By Lorenzo

The Silk Age of Eurasian trade  may have begun around 220 BC, with the unification of China under imperial rule and the shift to cavalry driving up demand for horses, but trade over long distances began millennia before that.

Copper arrives

While there is evidence of long-distance trade even among foraging societies–ochre, for example, travelled thousands of kilometres across Australia–it is with metals that trade begins in strategic materials, vital for sustaining complex societies in the face of external threats as well as making internal predation proceed more smoothly.

Copper mace head

Copper mace head

The development of pottery permitted the development of metal smelting, starting with copper–a relatively common metal with a low melting point. (There is no use of metal without developing pottery first.) The Copper Age saw the first long distance trade in metal, particularly to Mesopotamia, which had rich soils but not much else. The land between the rivers could produce food, and thus people, in sufficient numbers to sustain complex, highly organised societies and so considerable elite demand operating from surpluses extracted from peasant farmers. It also had plenty of clay for pottery and writing on tablets. Other goods, particularly metal, it had to trade for.

Bronze Age

Bronze mace head

Bronze mace head

If you add tin to copper you produce bronze, a harder and more durable alloy than copper on its own. The Bronze Age begins around 3600BC in Mesopotamia and the Fertile Crescent, around 3300 BC in the Indus Valley, around 3200BC in the Aegean, spreading slowly across Europe (by 1800BC in Central Europe, by 1300 BC the Atlantic coast), around 3150BC in Egypt and around 3000BC in China. From around 2300 BC, there is a flourishing Bronze Age civilisation in the Upper Oxus.

Dissemination of the technique (whether by direct learning, inference or independent invention) for producing bronze was slow. This is hardly surprising–something as public and obvious as farming only spread across Europe at the rate of about a kilometre a year, taking thousands of years to spread from Anatolia to Ireland. It is rather easier to be secretive about metallurgy.

Farming, surpluses and patriarchy

Another reason for the slow spread of farming is that farming is actually harder work than foraging (and less healthy, with more disease and a narrower diet), so farming mostly spread by spread of farmers (given that farming outproduces foraging by a large margin). Farming thus supported–in fertile river valleys–much higher concentrations of people. Being tied to plots of land with food that had to be stored across the seasons made farmers more easily exploitable–in the extraction of surplus sense.


It also made women more controllable. High density farming societies tend to be patrilineal (father-son inheritance) and patrilocal (daughters marry out) because the density makes women–the physically weaker and more reproductively vulnerable gender–more easily monitored and marrying-in sons-in-law (in matrilocal systems) are likely not as reliably committed to their new family–as fatherhood is more uncertain given the social freedom and status of women in matrilineal-matrilocal societies–compared to marrying-in daughters-in-law (in patrilocal systems) since motherhood is not in doubt.

The mutually-supporting combination of making male control of female fertility easier plus more reliable harnessing of male effort leads to the patrilineal-patrilocal conjunction being near-universal in high density agrarian societies. It is also dominant in herding societies as the physically stronger and less reproductively vulnerable gender manages the animals that are the dominant source of wealth, income and status.

The surplus-extracting elites in the river valley civilisations may have also partly purchased farmer submission by supporting patriarchal authority within farming families. The notion of proper order within the family supporting proper order beyond the family which is such a feature of the thought of Kong Qiu (or Kongzi, Kong Fuzi, K’ung Fu-tzu aka Confucius)–but is a recurring theme much more widely–may be as much implicit trade-off as justifying metaphor.


Even in early starter Mesopotamia, the ideal mix–10 parts copper to one part tin– for producing bronze only develops in Mesopotamia around 2800BC. Copper and tin are not found together, so trade was basic to the Bronze Age. Since bronze was such a vital strategic metal, rulerships tended to be deeply involved in the production and trading of copper and tin.

Coins had not yet been invented, so it is an age of labour-service rulerships and monumental construction (presumably to keep the labour busy in the off season and the ruler’s claims on labour service alive and well). It was an age of palace and temple-dominated economies; institutions big enough to organise and extract labour service and provide public goods (such as protection and mediation services).

A Deeply Dark Age

The Bronze Age ended in the Eastern Mediterranean in a truly dramatic collapse, a Dark Age much worse than that which afflicted Western Europe after the collapse of the Western Roman Empire. Literacy entirely disappeared from Greece (which is why the Greek alphabet is a derivation of Phoenician letters, and has nothing to do with the Linear B script of the Mycenaean period) while large areas of Greece and Anatolia remained at village level for centuries. There was neither the trade nor the effective local predation to support more complex societies.

Ramses III fighting off the sea peoples

Ramses III fighting off the sea peoples

The why’s of this collapse (around 1200-1150 BC) are still much debated–it was possibly a case of one damned thing after another–but the collapse of trade was basic to its depth (and possibly its cause), just as the collapse of trade was a basic feature of the post-Western Roman Empire Dark Age in Western Europe. That Bronze Age rulerships relied so much on trade for their weapons and armour made them vulnerable to trade disruption.

As is so often the case with major historical disruptions, superior technology also mattered. Iron in itself is only marginally stronger than bronze, but if the carbon content is high enough to be close to steel, it provides better armour and sharper weapons, if marred by a tendency to rust. Thus was the Bronze Age was followed by the Iron Age. While iron artefacts date back to 4000BC, the widespread use of iron–particularly in weapons–occurs in the Middle East after 1300BC. It is possible that the trade collapse, making tin much less available, forced more use of iron, a process reinforced by discovering how to make it strong enough for effective armour and weapons (i.e. quasi-steel). Alas, as with so much about the Bronze Age collapse, it is unclear what the causal sequence was.

Once effective iron, and particularly steel weapons and armour, could be constructed, village-level warrior bands could be quite effective with iron weapons while the armoured horse warrior had not yet emerged from various Iranian peoples (notably the Parthians, Sassanids and Sarmatians). Later still, with the rise of the mounted armoured warrior, Iron (and Steel) Age manorialism could also be based on village-level units, since the combination of horses-and-iron (and, even more, steel) could operate effectively on a somewhat lower scale, and with less population density, than bronze-and-chariots in extracting labour service and providing public goods (notably protection). The use of iron ploughs also encouraged the spread of more stationary (and so more elite-exploitable) forms of agriculture.

Iron Age recovery

But that was a much later development. Eventually, trade in the Mediterranean region revived from the Bronze Age collapse. This was the period when the Phoenicians first began to become important, venturing as far as the British Isles, especially for tin (people did not stop using bronze). Their coastal city-states seem to have benefited from the collapse of the Bronze Age rulerships and they dominated Mediterranean maritime trade until after the rise of the Greek city-states from 800BC. The Phoenicians are also the people who gave us the alphabet.

Phoenicians and Greeks: always willing to give trade a chance.

Iron is both relatively common and heavy, so tended not to be much traded [over lengthy distances], unlike its products (notably weapons). But even though Kipling’s baron might say that “iron, cold iron, is master of them all“, as outlined in previous posts, during the later Iron-cum-Steel Age other items dominated trade.

In the Mediterranean, the rise of coastal city-states was very much based on the revival of trade. As trade continued to increase, political units around the Mediterranean became larger in size. Eventually, with the creation of Imperial China under the Qin and Han dynasties, and the beginning of the Silk Road system proper, with the consequent increase in trade, the scene was set for one such state to absorb the entire Mediterranean world, putting it in the optimum position to tax trade. From this period onwards, Mediterranean and Middle-Eastern history–particularly its imperial history–operates according to the ebb-and-flow of the Silk Road system. Until, that is, the Great Transformation creates such a depth of trade connections that we can speak, for the first time, of genuine globalisation and the politics thereof (pdf).

Atlantic littoral Europe may have connected the world from the 1490s on, creating global history for the first time–with a genuinely global, rather then Afro-Eurasian, trading system–but it was only the Great Transformation that created a truly globalised world. Said Transformation also saw a surge in imperial expansion–reacting to the increase in trade–while also undermining empires, due to the increasing importance of (monetised) labour income.

To a startling degree, the history of us is the history of trade. Between the trade of foragers and the Silk Age of Eurasian trade–which was followed by the Silver Age of global trade and the Industrial Age of globalising trade–there was the age of copper and tin, when strategic metals genuinely dominated trade, followed, after an interlude, with a period of recovery and expansion as societies adjusted to the possibilities of iron and steel. On the way through, inventing coins and experiencing the transformations of the Axial Age. (The vast expansion in transactions not embedded in ongoing connections that coins permitted did probably have something to do with the intellectual transformations of the period; including religious and philosophical grapplings with how to manage societies where such transactions had become so dominant.)

Trade–the propensity to “truck and barter” with outsiders, with folk we have no deeper connections with–is not only central to our world as it is, it is central to how it came to be.


  1. conrad
    Posted June 28, 2013 at 1:05 pm | Permalink

    I love the picture of Ramses — not only trade was important, but fighting was too! It makes me realize what slack lives we have these days.

  2. Posted June 28, 2013 at 2:38 pm | Permalink

    [email protected] Yes, Egyptian official art left no doubt about Who Was Boss. And did so to a high standard.

    We are, indeed, in the Age of Comfort.

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