CIA

It's the story of an idea, the idea for an alternative to barter that resulted in the first monetary system and later led to the growth of economies and the invention of banking, insurance, and credit. The first thing to remember is that money, or currency as we call it, is essentially a tool to ease exchange and has existed since ancient times. It's almost impossible to know the exact start of currency since there are so many cultures and eras where it was used.