The main Roman currency during most of the Roman Republic and the western half of the Roman Empire consisted of coins including: the aureus (gold), the denarius (silver), the sestertius (bronze), the dupondius (bronze), and the as (copper).

These were used from the middle of the second century BC until the middle of the third century, a remarkably long time.

They were still accepted as payment in Greek influenced territories, even though these regions issued their own base coinage and some silver in other denominations.

Either called Greek Imperial or Roman provincial coins. During the third century, the denarius was replaced by the double denarius, sometimes known as the antoninianus or radiate, which was then itself replaced during the monetary reform of

Diocletian which created denominations such as the argenteus (silver) and the follis (silvered bronze). After the reforms Roman coinage consisted mainly of the gold solidus and small bronze denominations. This trend continued to the end of the Empire in the West. See also Byzantine currency.

About the featured coin:

JULIUS CAESAR. 49-48 BC. AR Denarius - approx 18mm ( weight 4.12 grams). First coin struck in the name of Julius Caesar. Military mint traveling with Caesar. Elephant right, trampling on serpent (The conquest of good over evil and/or Caesar's victory over the Gauls) / Simpulum, sprinkler, axe (surmounted by a dog's head), and priest's hat. (Caesar's possession of the office of Pontifex Maximus.)