Aureus

Roman gold coins

Gold coins were issued in Rome before Julius Caesar on a non-continuous basis. A first issue of gold coins, called oath gold, occurred around 220 BC. tracing the characteristics of the Greek-style quadrigates; the weight was 6 scruples, corresponding to 6.82 g.. The name derives from the scene represented on the back which illustrated the oath of two warriors on a little pig which was held by a third warrior: this scene should refer to the oath of allegiance following the peace of 290 BC. after the victory at Sentinum in 295 BC. of the Romans on the Samnites and their coalition.

A second series of gold coins, referred to as "mars/aquila", was minted in 209 BC. with a weight of 3, 2, and 1 scruple. The third series of gold coins was the one issued in 197 BC. in Greece favor of the consul Titus Quinctius Flamininus, consisting of a stater weighing approximately 8g.

The aureus in the Republican period

The first aureus of Roman design (denarius aureus) occurred at the time of Sulla's war against Mithridates (88-85 BC), with a weight equal to 1/30 of the Roman pound (10.8 g) and the gold presumably coming from war spoils.

As fractions the aureus had the quinarius (equal to half aureus) and the ratio between gold and silver was one aureus against 25 denarii. As a multiple of the aureus we had the quaternion, corresponding to 4 aurei.

In 61 BC, during the rule of Pompey, the weight of the aureus was then increased to 1/36 of a pound (about 9 g).

The continuous issuing of gold coins in Rome, however, began only after Caesar's conquest of Gaul and the availability of gold from its mines. In 48 BC, under Caesar, the weight of the aureus was first set at 1/38 (8.55g) and then at 1/40 of a pound (8.02g). This value remained stable throughout the period of the civil wars, up to the principality of Augustus.

The aureus during the empire

The mass of the aureus decreased to 1/45 of a pound with Nero's monetary reform and with Caracalla's reform the peso was further reduced to 1/50 of a pound.

The end of the aureus came in 309 with the introduction of the solidus as a gold coin by Constantine I. While the solidus was larger in diameter and thinner, the aureus was similar in size to the denarius, with which it often shared the same types.