The Age of Trade and Craft

Underneath the gods and the god-kings, beneath the monuments and the written prayers, ran a humbler layer that connected the first civilizations to one another and, in the long run, mattered as much as any of them: the layer of stuff, of raw materials and the crafts that transformed them, and of the trade routes along which both moved. This chapter is about that layer, because the story of the first cities is not only a story of temples and kings. It is a story of a shining black stone, a blue rock from a single mountain, a lump of tree-sap, and the discovery of how to pull metal out of stone, and of how those things stitched a scattered humanity into its first connected world.

Begin with obsidian, the volcanic glass that fractures to an edge sharper than any modern scalpel. It occurs naturally only at certain volcanoes, and yet obsidian tools turn up hundreds and even thousands of miles from any volcano, which means that from deep in the Stone Age, long before cities, people were moving it, hand to hand and valley to valley, across enormous distances. And here is the quietly miraculous part: because each volcano's obsidian carries a slightly different chemical fingerprint, modern scientists can pick up a blade found in an ancient town and say precisely which mountain, half a continent away, it came from. Through that fingerprinting we can watch the invisible web of Stone Age exchange light up across the map. Obsidian was only the beginning. Lapis lazuli, the deep blue stone the pharaohs craved for the tomb-masks of their kings, came from essentially one source on Earth in that era, the remote mountains of Badakhshan in what is now Afghanistan, and was carried something like four thousand miles to reach Egypt. Baltic amber, fossilized tree resin from the cold northern seas, traveled south to the warm Mediterranean. Jade was worked, independently and with reverence, in China, in Mesoamerica, and in New Zealand. Even salt, which we take for nothing, was so essential for preserving food that whole towns rose on it; the settlement of Solnitsata in what is now Bulgaria, built around a salt-production industry more than six thousand years ago, has a fair claim to be the oldest town in Europe, and the Roman soldier's pay, the salarium from which we get the word salary, may itself descend from an allowance of salt.

The trade in stones and resins was ancient, but the transformation that named the coming age was the mastery of metal, and it unfolded as a slow, world-altering sequence of discoveries. First, people learned to hammer the rare lumps of naturally pure copper they found into shape. Then, and this was the true leap, somewhere in the Balkans and the Near East around seven thousand years ago, they discovered smelting: that if you heat certain dull, ordinary-looking rocks hot enough, bright liquid metal runs out of them, that metal is hidden inside stone and fire can set it free. It is hard to overstate how magical and how consequential that discovery was; it is the foundation of every technology that followed, straight through to the device you may be reading this on. And then came the crucial refinement. Pure copper is soft. But mix molten copper with a small measure of tin, and you get bronze, far harder, that holds an edge and casts into tools and weapons and art of a quality copper never could. The Bronze Age had its name and its engine. But tin, as the next chapter will show, was rare and concentrated in only a few far-flung places, so the very recipe for bronze forced the civilizations that depended on it to reach across the world for the missing ingredient, and trade stopped being a luxury and became the arterial system of an entire interconnected age.

The metalworkers themselves must have seemed like sorcerers, and one particular material shows just how the ancient mind understood their art. Long before anyone could smelt iron from ore, the Egyptians and others possessed a little precious iron that fell, quite literally, from the sky, in the form of meteorites, and they knew its origin: the ancient Egyptian term for it translates as something like iron of heaven. The dagger buried with the pharaoh Tutankhamun has a blade of this meteoritic iron, a weapon forged from a fallen star, laid beside a king to carry into eternity. There is no better image for this whole chapter than that: the marriage of raw cosmic material, the craft that shaped it, and the meaning a culture poured into the result.

And it was not only goods that moved along these routes. Ideas moved, and technologies, and above all the supreme technology of writing, which, exactly like the eye and the pyramid, was invented independently more than once: the cuneiform of Sumer, the hieroglyphs of Egypt, the characters of China, and much later and entirely alone, the glyphs of the Maya in the Americas, four separate human inventions of the astonishing trick of making speech visible and permanent. Other crafts spread and deepened along the way. People had been fermenting grain into beer and honey into mead since deep in the Stone Age, at sites reaching back thirteen thousand years, arguably brewing before they were reliably baking, and some archaeologists seriously argue that the desire for drink helped drive the domestication of grain itself. They spun flax and wool into cloth and learned to dye it, and one dye in particular, a deep purple wrung in tiny quantities from a Mediterranean sea-snail, became so costly and so coveted that it would come to mark royalty itself, the origin of the phrase "born to the purple."

Step back and see what this humble layer accomplished. By the second millennium BCE, the appetite for tin and gold and lapis and purple and a hundred other things had drawn the separate civilizations of the last chapters out of their isolation and woven them, thread by thread, into a single connected system that stretched from the mines of Afghanistan to the palaces of Egypt to the workshops of Crete. Trade had built a world. It had also, without anyone intending it, built a dependency, a web so tightly knotted that a shock to any part of it could travel to all the rest. That brilliant, connected, and dangerously interlocked world is where our next chapter opens, and where, for the first time in the human story, we will watch such a world come crashing down.