Imperial Rome
by Priscilla Colombi

The monetary system reformed by Constantine did not undergo many changes. The solidus continued to be minted on a large scale whereas its fractions were struck rarely. Production of multiple aurei mainly for celebrations or gifts became more consistent. It seems that in the 370s about 225 tons of gold were in circulation. However, Magnentius issued lighter solidi than usual (= 3.80 grams) during the riot that enabled him to control most of the Western provinces (350-353 A.D.).

From 368 A.D. the letters OB appear next to the initials of the mint on the reverse of the solidi minted in Constantinople: it is the abbreviation of the adjective obryziacus (solidus implied), or of the noun obryzum, meaning "pure, refined gold". The Greek letters / numbers OB (= 72) could also indicate that the solidi are struck at 1/72nd of a libra. This kind of epigraphic innovation - used later by the other mints as well - shows the reintroduction under the Valentinian dynasty of a very high fineness for the gold coinage, higher than 99.01% with an increase in purity of more than 4% compared to previous series.

In 383 a new gold fraction is introduced, the tremissis, equivalent to 1/3rd of a solidus (= about 1.51 grams), in order to facilitate the circulation of gold coins in the economic exchanges and to counteract the lack of silver issues. During the 4th century, and even more so in the 5th century, there is a standardization of the reverse types (including also those of the gold series), and a focus on the image of Victoria. The initials AVGG or AVGGG, i.e. "of two or three Augusti", were in relation to the collegiality of two or three Emperors. On the obverse, the facing armed imperial portrait becomes a common type.

The monetary system established by the Valentinian dynasty will last in the West, with few changes, until the fall of the Empire (476 A.D.), and in the East until the reform of Anastasius (498 A.D.). In the minting of gold the tremissis becomes increasingly important: it will often be used in the new Romano-Barbarian kingdoms as well. This monometallic system based on gold lasts in the West until the last decades of the 7th century, when Charlemagne replaces it with a monometallic system based on silver.

Click on the images of the coins to enlarge them

di Costanzo II

di Magnenzio

Multiplo da due solidi
di Graziano

di Valentiniano II

di Arcadio

di Teodosio II

di Eudocia

di Zenone

di Sisibut
Aurei Longobardi, by E. A. Arslan (per gentile concessione)

© 2008 UCSC Milano