The earliest Roman currency was a bronze coin called the as. It weighed as much as a Roman pound, about 335.9 grams. Around 187 B.C. a silver coin called the denarius was introduced. During the Second Punic War (218 to 201 B.C.), a gold coin called the aureus was introduced.
The silver denarius was worth 16 of the bronze coins, and the gold aureus was worth 40 silver coins. Typically the gold and silver coins were used in official transactions, while bronze coins were used for more common exchanges. During the time of the Roman Republic, money was minted in the Temple of Juno Moneta. Our term "money" derives from Moneta.