by Simon Black
By the mid-6th century BC, Darius the Great was ‘King of Kings’, ruling over the vast Achaemenid Empire.
By that time, gold and silver had already been in use by earlier civilizations for thousands of years.
There are cuneiform tablets that are nearly 4,000 years old from ancient Sumeria which record commercial transactions made in gold and silver.
And subsequent civilizations– the Babylonians, Egyptians, Lydians, etc. all used gold or silver in commerce.