The Invention of Coinage
In the kingdom of Lydia, someone struck lumps of electrum — a natural gold-silver alloy — with a state mark guaranteeing their weight and purity. Before coins, every transaction required weighing metal and arguing about its quality; a coin let strangers trade without trusting each other, because they could both trust the stamp. Money became portable, countable, and taxable, and markets could form among people who had never met. The Greeks adopted it immediately, and within a century coinage had spread across the Mediterranean.
The path or medium of exchange moves, and a place or power rises or declines because it sits on or off the new route.