Around 9000 BC people paid for good with animals like cows,sheep and camels. Some societies used vegetables and plants,too. Then in 1200 BC people in China started using shells as money-mainly the cowrie shell. Soon other countries began to do the same. The cowrie shell was very successful. It was used longer and in more places than any other currency in history.
The next development was in 1000 BC,when China started making bronze and copper cowrie shells. It wasn't long before the Chinese made round coins out of metal. The very first coins often had holes in them so that people could pass a piece of string through them to keep them together. By 500 BC metal coins had begun to appear in countries like Persia and Greece, and later in the Roman Empire.