Copper had been known for thousands of years (it was hammered into use in Anatolia from around 7500 BCE), but it was soft: it bent, it would not hold an edge under hard work. From around 3300 BCE, some societies discovered that alloying copper with roughly 10% tin produced bronze — a much harder material that could be cast into complex shapes and held a consistent edge. This was a technological revolution with no announcement: stone simply disappeared from weapons, farm tools, ritual vessels, and ornaments.

The critical bottleneck was tin. Copper is present in many regions; tin is rare, and tin ore generally has to travel from its source to workshops far away. Tin deposits from Cornwall to Afghanistan, from Anatolia to Iran, had to meet at the foundries. This forced the first true long-distance trade networks of the Old World into existence; metallurgists, caravan merchants, and palace bureaucracies that kept inventories are the new professions of this economy.

The Bronze Age is not a transition but an epoch: between roughly 3300 and 1200 BCE, distinct bronze cultures rose and matured around the Mediterranean, in Mesopotamia, Egypt, the Indus Valley, China, and Europe. In Anatolia, Early Bronze Age sites such as Alacahöyük and Hattusa carry the region's metallurgical mastery; the Alacahöyük "sun discs" and animal-figure standards are among the artistic peaks of the period. The Bronze Age gives way to the Iron Age in the great systems collapse of around 1200 BCE.