Technology & Medicine › Ancient world › Bronze metallurgy (the Bronze Age)
Iron smelting (the Iron Age)
c. 1400 BC (Anatolia); widespread after 1200 BC· Invention or discovery· Tools, energy & materials
Mostly agreedGood evidence; some details, dates or numbers uncertain.
Extracting iron from ore with charcoal fires, yielding a metal far more abundant than copper or tin.
See it on the Technology & Medicine map →How it works
Iron ore is common almost everywhere, unlike tin. But iron melts at about 1,540 °C, beyond ancient furnaces, so smiths heated ore with charcoal into a spongy lump called a bloom and hammered out the waste. Adding carbon made steel, and quenching it in water hardened it. Iron was smelted in Anatolia by about 1400 BC, perhaps earlier, and spread widely after 1200 BC, when Bronze Age trade networks collapsed. China was casting molten iron by about 500 BC.
Why it mattered
Cheap, plentiful iron put strong tools and weapons, from plows to swords, into ordinary hands, and later became the backbone of industry.
How we know
Iron objects and slag from Anatolian sites such as Kaman-Kalehöyük; Hittite letters mentioning iron; Tutankhamun's dagger of meteorite iron; early Chinese cast-iron tools.
Still unknown or debated
The old idea that the Hittites guarded an iron secret is largely rejected; why iron spread after 1200 BC is still debated.
Connections (3)
▸Bronze metallurgy (the Bronze Age) gave way to Iron smelting (the Iron Age)Well documented
The connection
Bronzesmiths' furnaces, charcoal and bellows were the starting point for ironworking, though iron needed different handling: hammering a hot bloom rather than pouring molten metal. When long-distance trade collapsed around 1200 BC, tin became scarce and local iron ore attractive. Over centuries iron replaced bronze for everyday tools and weapons.
When and how
Anatolia and the eastern Mediterranean, about 1400 to 1000 BC, spreading through Europe, Africa and Asia over the next thousand years.
How we know
Excavated layers show iron tools increasing as bronze declines, and Hittite and Egyptian records treat iron as precious before 1200 BC.
Debates and open questions
Whether tin shortages drove the switch, or improving iron skills simply won out, is still argued.
▸Iron smelting (the Iron Age) was transformed by the Bessemer steel processWell documented
The connection
For about 3,000 years smiths made iron by smelting ore with charcoal, then hammering it. Steel, iron with just the right amount of carbon, was costly and made in small batches. Bessemer blew air through molten pig iron, burning off carbon and impurities in about 20 minutes, turning steel into a bulk material.
When and how
Ironmaking from Anatolia about 1400 BC; Bessemer in London, 1856, with his own steelworks in Sheffield from 1858.
How we know
Production figures: world steel output rose from under one million tons around 1870 to roughly 28 million by 1900, by estimates.
Debates and open questions
Chinese ironworkers had removed carbon from cast iron by blowing or stirring for centuries; whether any of that knowledge reached Bessemer or Kelly is unproven.
▸Iron smelting (the Iron Age) supplied cheaper metal for Gunpowder weapons and cannonMostly agreed
The connection
Early cannon were cast in bronze, strong but expensive, or built from wrought-iron bars bound with hoops, like a barrel. Chinese foundries cast iron guns by the late 1300s, and England learned to cast reliable iron cannon in 1543. Cheap iron let states arm ships and forts with many more guns.
When and how
Bronze and wrought-iron guns in Europe from the 1320s; cast-iron cannon in Ming China by the late 1300s and in Sussex, England, from 1543 under Ralph Hogge.
How sure are we?
Surviving guns, foundry records and naval inventories show the shift; England's cheap iron guns armed its navy and became a major export.
Debates and open questions
Iron guns were cheaper but heavier and more likely to burst, so bronze stayed preferred for some uses into the 1700s; how fast the switch happened varied by country.