I had not realised before that the Bronze Age Collapse was literally *caused* by iron. Bronze age powers like the Egyptians, Hittites and Babylonians used bronze weapons, made by combining copper and tin. Tin was so scarce that only the richest and most powerful groups could access it and the bronze weapons it allowed. (Tin was so rare that it was being transported from Cornwall to the Middle East more than 1000 years BC.) The scarcity of tin gave these empires a near-monopoly on violence. Iron weapons are not actually any better than bronze ones – they're not stronger or easier to work with, as I'd assumed. They're just much, much easier to mass produce once you have bloomeries, which are the first furnaces that were hot enough to melt iron in a way that made them useable for weapons. Bloomeries meant that iron ore, which was widespread, could be used to make weapons anywhere. That led to warlords, bandits and city-states rising in a massive decentralization of military power, which the Bronze Age empires were unable to resist. After the invention of the bloomery, skeletons show a measurable increase in weapon-inflicted injuries. 'Destruction layers' with bones and signs of burning have been found from this time at archaeological sites including Troy. Ancient writers – including Herodotus, Ovid, and the writers of the Old Testament – believed the invention of iron had unleashed a new age of violence. New at Works in Progress, WEAPONS OF MASS DECENTRALIZATION: how iron itself brought about the Bronze Age Collapse. And what technologies could do the same today? worksinprogress.co/issue/wea…