The History of Currency & Exchange
Before Money: Barter
The earliest human economies ran on direct barter — trading goods for goods. But barter has a fundamental problem: the 'double coincidence of wants'. To trade, you need someone who wants exactly what you have and has exactly what you want. As societies grew, this became impractical.
Commodity Money
The first 'money' was commodity money — items that had inherent value and were widely desired: cattle, grain, salt, shells, and beads. The word 'salary' comes from the Latin 'salarium', believed to relate to salt payments to Roman soldiers (though historians debate this). The word 'pecuniary' (relating to money) comes from 'pecus', Latin for cattle.
The First Coins
Metal coins appeared in Lydia (modern-day Turkey) around 600 BCE — electrum (a gold-silver alloy) stamped with official marks to certify their weight and purity. Coins solved barter's problems: they were durable, portable, divisible, and widely accepted. Within a few centuries, coinage spread across Greece, Persia, India, and China.
Paper Money
China invented paper money (jiaozi) during the Tang Dynasty (618–907 CE) as a convenience for merchants carrying heavy coins. When Marco Polo saw paper money in the 13th century, Europeans found the idea bizarre and untrustworthy. Europe didn't widely adopt paper currency until the 17th century, with the Swedish Riksbank (1661) issuing the first European banknotes.
The Gold Standard
Throughout the 19th and early 20th centuries, most major currencies were pegged to gold — each unit of currency could be exchanged for a fixed amount of gold. This kept exchange rates stable but limited governments' ability to respond to economic crises. The US left the gold standard in 1971 under Nixon, completing a global shift to 'fiat' currency backed by trust and government decree, not metal.
Modern Exchange Rates
Today, currency values float against each other based on supply, demand, interest rates, inflation, and market sentiment — changing every second on global forex markets. Over $7.5 trillion is traded in currency markets every single day, making foreign exchange the largest financial market in the world.