The Roman currency system included the 'denarius' (plural: denarii) after 211 BC, a small silver coin, and it was the most common coin produced for circulation but was slowly debased until its replacement by the antoninianus. History The denarius was first struck in or about 211 BC during the Roman Republic and at the same time as the Second Punic War, with a weight of 4.5 grams on average at the time or 1/72 of a Roman Pound. It remained at this weight for a while and then decreased to about 3… (More on Denarius)