| Back to The Imperial Period (27 BC to 476/491/498 AD) | This page is part of the article Getting Started with Roman Coins | Forward to Monetary Reform of Caracalla in 215 AD |
Imperial coinage started with the monetary reform of Augustus in 23 BC which standardised on the following denominations:
| Metal | Denomination | Value (Asses) | Value (Denarius) | Weight |
| Gold | Aureus | 400 | 25 | 7.8g |
| Quinarius aureus (Half Aureus) | 200 | 12.5 | 3.89g | |
| Silver | Denarius | 16 | 1 | 3.79g |
| Quinarius | 8 | ½ | 1.73g | |
| Orichalcum | Sestertius | 4 | ¼ | 25g |
| Dupondius | 2 | 1/8 | 12.5g | |
| Copper | As | 1 | 1/16 | 10.5g |
| Orichalcum | Semis | ½ | 1/32 | 4.6g |
| Copper | Quadrans | ¼ | 1/64 | 3.6g |
The old bronze denominations that survived were now minted either in copper or orichalcum (a brass alloy of 80% copper and 20% zinc), and the Sestertius was reintroduced using orichalcum instead of silver.
| Denomination | |
| Aureus 7.86g |  |
| Quinarius aureus (Half Aureus) 3.94g 15mm |  |
| Denarius 3.35g |  |
| Quinarius 1.78g |  |
| Sestertius 25.28g |  |
| Dupondius 14.31g |  |
| As 9.17g |  |
| Semis 5.74g |  |
| Quadrans 2.77g |  |
The Dupondius and As were of a similar size, but could be identified at the time by their colour. Orichalcum has a yellow colour, and copper a red colour. This sometimes presents difficulties for collectors as the colour can now be obscured by patina. In 66 AD, Nero changed the portrait on the Dupondius so that the emperor had a radiate crown instead of the classical laurel crown (for women, a crescent under the bust).
Coins from Augustus onwards feature a portrait of the emperor (or a relative) on the obverse. The taboo of having a living person on a coin was comprehensively broken during the Imperatorial era.
The monetary reforms of Augustus lasted for about 200 years. In that time the coins were debased by Nero in 66 AD amongst others, and by 200 AD purity had declined by as much as 50%. It should be noted that some emperors, such as Pertinax, tried to reverse the debasement.
Article Navigation
| Back to The Imperial Period (27 BC to 476/491/498 AD) | Up to The Imperial Period (27 BC to 476/491/498 AD) | Forward to Monetary Reform of Caracalla in 215 AD |
