Iron
“With bronze we built kingdoms. With iron we built empires.”
Iron is a strategic resource that unlocks the most powerful military units of the ancient and classical eras. Deposits of iron ore are hidden on the map until Bronze Working technology is researched, at which point they become visible and can be exploited. Control of iron is essential for any civilisation with military ambitions – without it, your armies are stuck with weaker bronze-age units while your rivals field armoured swordsmen and mounted knights.
Stats
| Yield Bonus | +1 Production |
| Revealed By | Bronze Working |
| Resource Type | Strategic |
Required For
| Unit | Notes |
|---|---|
| Swordsman | Core melee infantry of the classical era |
| Knight | Heavy mounted unit, powerful in open terrain |
| Legion | Roman unique unit (replaces Swordsman) |
Strategy
Iron is the first strategic resource you will encounter, and its importance cannot be overstated. The moment you research Bronze Working, iron deposits will appear on the map – and the scramble to secure them begins. A civilisation with iron can build Swordsmen, which are dramatically stronger than Warriors. A civilisation without iron is stuck with Warriors until they can trade for it or conquer a source by force.
When iron is revealed, immediately assess whether any deposits fall within your existing city borders. If not, consider settling a new city specifically to claim an iron deposit, even if the city site is otherwise mediocre. The military advantage iron provides is worth a suboptimal city location. If iron is near a rival’s territory, you may need to act quickly – either through diplomacy, forward-settling, or outright conquest – before they claim it first.
Iron remains relevant deep into the game. Knights require iron in addition to horses, meaning a civilisation planning a medieval-era cavalry push needs access to both resources. Losing your iron supply mid-war – through pillaging, city capture, or trade embargo – can cripple your military production at the worst possible moment. Always protect your iron tiles and consider building redundant access through multiple cities if possible.
Historical Background
The transition from bronze to iron was one of the most significant technological shifts in human history. Beginning around 1200 BCE in Anatolia and the eastern Mediterranean, the Iron Age spread across Eurasia over the following centuries. Iron ore was far more abundant than the tin and copper needed for bronze, making iron weapons and tools accessible to a much wider population. This democratisation of metal had profound social consequences – iron ploughs broke heavier soils than bronze ones, iron weapons equipped larger armies, and iron tools enabled construction projects of unprecedented scale.
The Hittites of Anatolia were among the first to master iron smelting, and they guarded the technology jealously, understanding its military significance. When the Hittite Empire collapsed around 1180 BCE, iron-working knowledge spread rapidly throughout the Mediterranean and Near East, ushering in a new era of warfare dominated by iron swords, spear points, and armour. The Roman legions, arguably the most effective military force of the ancient world, were built on the foundation of superior iron equipment – the gladius sword and the lorica segmentata armour that gave legionaries their fearsome reputation.