The Romans excelled at many things, including the production of coinage. They issued coins in large quantities at mints strewn across their vast empire, often far from the capitals of Rome and Constantinople.

Sometimes their coins were products of “moving mints” or mobile “military mints,” but most often they were struck at established mints located in cities. Some of these were provincial mints that issued coins for local or regional use, and others were imperial mints that made coins for general use throughout the empire.

The provincial mints numbered in the hundreds, and represent a field all their own. In this column, we’ll focus on the imperial mints that produced the lion’s share of Roman coinage, including silver denarii and double-denarii, gold aurei and solidi, and a variety of base metal and billon coinages.

Early in imperial history the most significant imperial mints were in the capital of Rome and in the city of Lugdunum (modern Lyons in France). By 15 B.C., it seems Lugdunum had become the chief mint for imperial gold and silver, replacing Rome, which at that time produced only base metal coins. This arrangement persisted until some point between A.D. 14 and 69, when Rome once again became the principal mint for precious metal coins.

Precisely when this occurred is not known, but afterward the Lugdunum Mint was largely inactive until its renaissance in the later third century. In the interim, Rome resumed its traditional role as the principal mint of the empire, and its importance did not begin to fade until the mid-third century.

Interestingly, imperial-style bronzes were also issued at a mint in Thrace or Bithynia with some regularity between the reigns of Claudius (A.D. 41 to 54) and Titus (79 to 81). These coins tend to mimic issues of Rome, yet the style and fabric are peculiar enough to distinguish easily.

A great expansion in the number of active mints occurred during the civil war of 68 to 69. Usurpers in Spain, Gaul, Germany and North Africa produced coinage at mints principally in Italy and those provinces. When the war ended, all of these temporary mints were closed.

The victor in the civil war, Vespasian (69 to 79), had come to power in the East with the help of loyal soldiers in Asia Minor, Syria, Judaea and Egypt. Thus, it is not surprising that mints in these regions (which for centuries had produced Greek and Roman provincial coins) began to strike imperial coins.

Ephesus in Asia Minor and Antioch in Syria turned out to be the two most significant of these mints, expanding upon the legacy of other Roman mints in the East that issued silver coins — notably Pergamum and Caesarea. Though the silver coins of those two mints bore Latin inscriptions, they were not strictly imperial since the types were not patterned after those of Rome, and some of the denominations were never produced in the capital.

The true proliferation of imperial mints, however, did not begin until the mid-third century A.D. At this time, the focus of emperors shifted from Rome to border regions in the West and population centers in the East. As the number of imperial mints grew, provincial mints gradually were phased out. After 276 the only provincial mint left was Alexandria, Egypt, and even its production stopped by about 298, after which it only struck imperial coins.

By the late third century, Mint marks began to appear on Roman coins with increasing regularity, and by the early fourth century they were a standard feature. This makes collecting Roman coins by mint a more precise task, as most of the guesswork of earlier periods is eliminated. The use of Mint marks on this scale reflects the increasing complexity of the Roman bureaucracy, which worked hard to control coin production.

By late in the reign of Constantine the Great (307 to 337) we can draw a fairly good map of the empire based upon mint locations. In the Western provinces these included London, Lugdunum, Arelate and Trier. All were important mints of the era, with Lugdunum and Trier producing especially large quantities of coinage.

In neighboring Italy, the mint of Rome was still very productive, as were those based in Aquileia and Ticinum. For a brief period, circa 308 to 313, a mint was also in operation in Ostia, the port city for Rome. In North Africa, a mint was also active at Carthage under Constantine’s early co-rulers and rivals.

The Balkans and Northern Greece were important as recruiting grounds for soldiers, buffers against barbarian invasion across the Danube, and as regions for settling conflicts between rival emperors reigning in the East and the West. Not surprisingly, four active mints were located here: Siscia, Sirmium, Serdica and Thessalonica.

Four other mints — Heraclea, Constantinople, Cyzicus and Nicomedia — were situated a little further East, where Europe and Asia are separated by a body of water called the Propontis. All were major mints in the later Roman period, with Constantinople serving as the capital of the Roman and Byzantine world after its formal dedication by Constantine the Great on May 11, 330.

Further south, two active mints remained: Antioch in Syria and Alexandria in Egypt. Both cities were critical to the economic and military needs of the empire, so it is not surprising that their mints issued great quantities of coins.

The abundance of Roman mints, as illustrated in this brief survey, not only demonstrates the breadth and sophistication of coin production in the empire, but speaks volumes about the Romans themselves. For numismatists, these coins and their distinctive mint signatures are a perfect way to introduce any collector to the many charms of ancient coinage. ¦