The very earliest coins were pieces of precious metal that were stamped with a design to guarantee their purity and weight. It is thought that the first coins first appeared in the mid 500s BC in Asia Minor.
Local rulers had to pay Greek mercenaries a set weight of precious metal at the end of their contracts, and to ensure the correct amount was paid, coins were used. These pieces of metal were generally stamped with an animal head on one side, perhaps indicating the person who issued them, and an abstract design on the other signifying the weight.
The first coins to be issued with the intention that they would be used as money were those minted by King Croesus of Lydia, a rich and powerful Greek state on the west coast of what is now Turkey.
These coins, from c550 BC, were small gold pieces stamped with a lion and a bull. King Pheidon of Argos minted silver coins stamped with a turtle, and some claim that he produced his coins before Croesus, but the dates when Pheidon lived are disputed.