A quick read of Pliny’s Naturalis Historia bk33 immediately gives us indication that by the 1st century AD century AD, metals were the material which was considered of highest value, even more so than cereals:
“WE are now about to speak of metals, of actual wealth, the standard of comparative value, objects for which we diligently search, within the earth, in numerous ways. In one place, for instance, we undermine it for the purpose of obtaining riches, to supply the exigencies of life, searching for either gold or silver, electrum or copper….”
The earliest form of Roman coinage (if such they can be called) was the Aes Rude from the 8th through the 4th century BC, ie during the period of the Ancient Roman kings. It was essentially a lump of bronze, a shapeless ingot which would later acquire a standard weight and shape.
Rome during the 8th-4th centuries wasn’t the most advanced Italic civilisation in terms of trade; quite the opposite, a look at the wine trade is a good example of how civilisations such as the Greeks and Etruscans had already developed significant trading routes across the mediterranean and around the Italian peninsula (let’s not forget that some of the early kings of Rome were in fact Etruscans). So whilst the Romans were undertaking trade on a relatively small local scale we can imagine the peoples around them having already developed means of enabling bulk trade across significant distances.
An example of this can be had from a statement by the 4th century BC historian Theopompus, (which has reached us via a 2nd Century BC quote by Athenaeus) when talking about the price tag attached to the highly valued purple dye: “”Purple for dyes fetched its weight in silver at Colophon in Asia Minor”.
The Aes Rude “lump” was eventually replaced by proper ingots, made with an official stamp, standard weight and size, called “Aes Signatum” (weighed 1.6kg). The Aes signatum gave way to “proper” coinage of standard weight and composition, the “Aes grave” (weight 320g-330g) around the year 290BC.
The high degree of sophistication reached by roman coinage is apparent to all: the coinage enabled common trading over an area at least as large as the modern US or the European community, this brought benefits in terms of liquidity and growth of the economy of Rome and the empire.
Coinage also helps us gain an idea of the relative weakening of the Roman economy as the weight and purity of the metals employed in coinage varied in line with the varying fortunes of the empire. For example, as mentioned above, the early aes coin weighed in the region of 330grams in the year 290BC, by the time of the wars against Hannibal (second Punic war, around 210BC) its weight had been reduced to 40grams.
In contrast with the modern world where coins are minted for change, coinage in the ancient world, coins were the principal means of monetary exchange, the value attached to them being equivalent to the value of the metal they were made of.
The proto coinage was essentially shapeless lumps of bronze metal. Coinage throughout antiquity , republican and imperial Rome frequently employed Copper, Silver and Gold even with a high level of purity. Inflationary pressures or lack of resources meant that alloys were also frequently used; for example copper alloys (eg 80% Cu and 20% Zn) or gold/silver (electrum) alloys. Bronze was the basic alloy used throughout the history of Roman coinage.
Increasing need for accuracy and controls meant that these metal exchange tokens were progressively cast into ingots of a given shape, weight and with a given image or symbol to guarantee their authenticity. Weight, particularly during the imperial system was based on the standard Roman pound, ounce and scruple. A roman pound weighed about 327.5 grams. An ounce was 1/12th, and scruple 1/24th.
A closer look at the coins of ancient Rome
Roman coins imperial mintsCoins in ancient times were manufactured by one of two means, either by casting (pouring the molten metal into a mould) or stamping. The casting process was less commonly used because it tended to make it more difficult to include intricate imagery on the coin face and as such made the coin easier to imitate. Stamping was hence a more common means of issuing coinage: the metal disks were made by casting and the image/artwork was then pressure stamped onto the two faces. There are also some cases of coinage issued in the 1st Century BC of laminated coins, ie where a cheaper metal was used for the core and a more noble metal used for the outer facing. A similar (but more sophisticated and durable) technique is used nowadays for example in British 2p coins where the core is ferrous and the outer skin is copper.
Archaic coinage across Italy was greatly varied, particularly when there was still a mixed presence of Greek colonies and Italic indigenous peoples. It was only into the 2nd and 1st centuries BC, subsequent to the second Punic war that marked the complete conquest of Italy and its islands and that coinage across Italy was unified under a single (Roman) system.
The emission of coinage was strictly controlled by the Roman senate and specifically chosen magistrates. It is these magistrates who signed the coinage to demonstrate their lawfulness either by way of symbols or by literally printing their name onto it. Hence coinage (until emperor Aurelian) has the letters “SC” standing for “senatus consultus” ie with approval of the senate.
As ancient Roman names became longer and more complex to identify individuals more clearly, so too did the inscribed names on coins. Personal identification of coins also developed in terms of portraits and imagery: republican coinage tended to show the image of deities such as the goddess Minerva, the god Mars, Janus, Venus, the goddess Rome or even the prow of ships.
Later coinage, beginning with Julius Caesar and throughout the imperial age increasingly displayed the profile portraits of the ruling classes associated with the magistrate issuing the coinage, ie the emperor, his ancestors, immediate family or even generals and dignitaries he wished to honour, whilst the reverse side of the coin would display a monument, public work, an event, or a even deity somehow associated with that ruler/person. It is therefore easy to see how coinage might be used for propaganda purposes. From around 240 AD the imagery had increasingly military connotations and by around 310 the portrait image would be modified to enhance the apparent strength and power of the individual.
It may be noticed that the emperors and dignitaries displayed on imperial roman coins wore a wreath or Roman crown of various sorts. These stood to represent various types of honour or meanings. Also worthy of notice during the imperial age is that it became common practice to include the year of rule of the emperor (“tribunicia potestas”), hence enabling coins to be easily dated.
As can be imagined, a particularly important reform of Roman coinage occurred at the very beginning of the imperial period, during the reign of Emperor Augustus. The general format and subdivision of coins lasted well into the 3rd century AD and included coinage of gold, silver and bronze.
An idea of how coinage was subdivided is given in the table below.
Gold: Aureus (7.8grams weight)) & quinarius aureus which was half it’s weight (3.9 grams, worth 12.5 denarii)
Silver: Denarius (3.9 grams) and Quinarius ( half a denarius, 1.9gr)
Bronze: Sestertius (27.3) and Dupondius (13.6)
Aes (10.9 grams) and Quadrant (1.7qr)
Nero’s reform of Roman coinage
There were of course a number of reforms to the system, the first of which by Emperor Nero who around 64AD (the year when fire struck Rome)…
reduced the weight of the golden Aureus to 7.3gr ie by half a gram (6%) – a good saving for state coffers
Reduced the weight of the silver Denarius to 3.4grams and reduced in silver purity by introducing 5-10% copper.
The Bronze Sestertius and Dupondius had an image change, showing a crown on the emperor’s head.
Bronze/alloy coins often had the symbol II, I and S shown on them for dupondius (II), aes (i) and half aes (S)
The Reform of Caracalla (214AD) introduced two new coins of which the antoninian became the most diffused coin in the empire and as such it is also a great example of the progressive decline of the Roman economy as the coin lost quality, became lighter and devoid of silver.
The double aureus
The antoninianus weighing 5.1gr of silver & bronze in equal proportions worth two denarii
Imagery on the reverse of these coins was strongly linked with glorification of the military.
Around 274AD Emperor Aurelian made a concerted effort to increase the quality of Roman coinage both in terms of the metal and weight as well as quality of the artwork.
The aureus was brought back to its old weight
Minted new dupondius, sestertius and aes
Introduced a symbol relating to the mint which had put the coin into circulation
In 294 AD Emperor Diocletian undertook a further reform:
The aureus was reduced from 1/50th to 1/60th of a pound (5.5gr)
A fresh silver coin was introduced “argenteus” of similar weight and quality to Nero’s denarius. 1/96th of a Roman pound ie approx 3.4gr
Introduced the “follis” made of bronze with a small percentage of silver weighing 9-12gr.
Around the years 307-310 the weight of the follis was reduced to around 7gr and under Maxentius (Constantine) subunits of it were introduced (half and quarter).
In 312AD Emperor Constantine introduced further and general reform of the Roman monetary system:
Introduction of the gold “solidus”, of reduced weight (4.5gr) which was to last into the medieval ages as a fundamental unit of reference.
Introduction of two silver coins:
Siliqua, 1/96th pound = 3.4 gr.
Miliarense, 1/72 pound = 4.5gr
The follis reached about 3.4gr by 317AD and in 330AD was reduced to 2.7gr and in 335AD to 1.7gr.
Emperor Constantine’s sons Constantius II and Constans introduced some further reform of their own in 348, introducing two fresh bronze coins. As the follies had dramatically shrunk by this time one of these coins, the centenionalis was introduced but only lasted a relatively short period of time.
As the name of bronze coinage of this period is unclear they are generally classified under the classes Aes I, Aes II, Aes III and Aes IV. The last two being particularly smaller.
The reigns of Valentinian and others saw minting of bronze coinage of ever decreasing weights beginning with two types of Aes 3 type with inscriptions “Gloria Romanorum” and “Securitas Republicae”.
The Aes 4 were truly small coins which saw the end of the Roman empire of the west. They were of approximately 1 scruple in weight, ie about 1.1gr.
Coinage after the fall of the Roman empire of the West:
It is striking and perhaps surprising that the Roman coinage system remained in use both in the roman-barbarian period of rule which followed the fall of the Roman empire as well as the oriental half of the empire (Byzantium/Constantinople), clearly with some later reforms and modifications of their own.