The Imperial Roman Economy, Hoarding, Gresham's Law and All That

By Historia

All the coin photographs in this article are shown to the same scale, for comparison purposes. Details of all the coins can be found elsewhere on the Historia web-site.

With our paper money, credit cards, internet banking and sophisticated investment opportunities, it's difficult to imagine what it was like when all our money was in the form of gold, silver and bronze coins. A simpler age maybe? Everyone knows that ancient silver and gold coins were worth their weights in those metals. But what did this mean in practise? The Roman Empire lasted for hundreds of years, so how was money actually used over that period? Political and economic conditions changed enormously throughout the life of the Empire, so what may be a valid model for one point in time may not be valid for another.

An amazing number of coins have survived until the modern era, either via hoards or single lost coins. This mainly reflects the size of the Empire and the vast number of coins that were issued. With this large corpus of coins is should be easy gauge how money was used and how it was regarded by the users. Unfortunately, this is not always the case.

This article tries establish the real facts behind the Roman monetary economy and what hoards can tell us. The Roman system of coinage does get very complicated, so it is not intended to explain every issue or denomination of coins in depth. Some of the ideas put forward may seem to be a bit contentious but remember that new finds and scholarship often change long held views. The aim of this article is to 'read between the lines' and present an overview of an exceedingly complicated period in monetary history.

Before we describe the history of Roman Imperial coinage, we will first examine some related topics. If you are unfamiliar with Roman coinage, you might like to fast forward to the Beginning of coinage in Republican Rome chapter, before returning here.


The dictionary definition of "value" is "The amount (of money, goods or services) that is considered a fair equivalent for something else". In other words "value" is a comparative term. So if we say a coin has a value of one Euro, we are entitled to ask, "compared with what?".

When all the different currencies of Europe were replaced with the Euro, every country in Europe (but not Britain!) used Euro coins or multiples of. However, that did not mean that the price of a loaf of bread was the same in every country, or even every city. The differences were (and are) even more marked for items such as houses. In other words, the value of the Euro, compared with items being bought, is variable and is affected mainly by market forces.

The Euro is, of course, a token coin but the Roman Imperial coinage was based on two precious metals, silver and gold. Such a system is known as bimetallism. The trouble with such a system is that gold and silver coins need to maintain a value with each other as well as a fixed value with the goods or services they might buy. External influences, such as a movement of bullion prices of gold or silver might affect this balance.

In the Roman Empire, coins were 'sold' through an official money-changer. That is to say, if someone wanted change for a gold aureus, he would have to take it to a money-changer, where he would receive 25 silver denarii, less commission. In that way, the exchange rate between gold and silver could be maintained at the official rate. That worked fine in stable economic conditions. The two types of coins effectively serviced two economies, the silver was used for the everyday necessities of life and the gold was used for trade and as a store of wealth for the better off. Provided the "value" of each type of coin remained roughly equivalent, there was no problem. However if prices (in denarii) in the market place rose, that distorted the relative values of gold and silver and the exchange rate between the two currencies would have had to have been altered or some other measure taken to achieve equilibrium, otherwise a run on gold might have ensued as well as other economic nasties.

The value of coins throughout the Roman Empire must have varied in terms of what they could buy, geographically and over time, as does the Euro today. However, the cities of the East, that is to say Greece, Asia Minor and the Middle East were a special case. They were allowed by their Roman overlords to continue the tradition of minting their own coinage. The minting of silver coinage was restricted to a few places, producing coins such the tetradrachm, shown below, equivalent to 4 denarii. Minting of base metal coins took place in most cities but only on an occasional basis, and were only intended to circulate locally. Whether these coins had any fixed value relationship with the silver coinage is unclear. It seems that there were moneychangers in these cities who exchanged imperial coins for the local money (silver or bronze). The eastern coinage is usually known as 'Provincial' or 'Greek Imperial' coinage.

Examples of Provincial coinage
"Greek Imperial" issues: (1) Silver tetradrachm of Philip I, 244-249, minted in Antioch
(2) AE27 of Gordian II, 238-244, and wife Tranquillina, minted at Messembria, on the Black Sea.
Silver coins were intended for circulation in the east, while bronze coins were strictly local issues.

Bullion and Face Value

When they were invented in the latter half of the 7th Century B.C., silver, gold and electrum (a mixture of gold and silver) coins circulated at bullion (metallic) value. Once people had become familiar with coins with their official markings, the coins could become accepted at face value (the value implied by the markings and size of the coin, such as a value of one drachm) without recourse to weighing, provided they were used locally. However, one of the main advantages in using coins is that they could be used for trade outside a country's borders. However, once a coin had crossed into another country, it had effectively become bullion (though not neccessarily melted down). The smaller the country or city state, the more the weights and purity of the coinage had to be maintained if it wanted to trade with it's neighbours. This is the reason for the many bankers marks and test cuts in early coinage.

Token Money
"coins of the regular issue having greater face value than the value of their metal content."
Collins English Dictionary

The definition in most dictionaries is somewhat unsatisfactory. Without doubt, the money used throughout most of the world today, is token money. Banknotes and coins have only a tiny intrinsic value. They are simply "tokens" representing Pounds or Dollars, which are themselves just names in the national consciousness, mostly not even any longer tied to holdings in the national bank.

However, Roman Imperial gold and silver coins also had a greater face value than their metal content, yet they are not considered to be token money. Ironically, modern British 2 Pence coins and US Cents have a face value that is near to their metallic value, yet they are still token money.

The only way out of this conundrum (at least for this article) is to define non-token coins as those having their value defined by reference to the amount of gold or silver in them, even though those amounts may vary from time to time, and values compared with bullion may change.
As we shall see below, Roman coinage was late in starting and developed in a much different ways than the Greek model. When Rome was just a city-state amongst several Greek colonies in Italy it was not highly monetised. Silver coins were copied from it's Greek neighbours more to demonstrate it's growing independence and growing power than for the purposes of trading. This is shown by the large numbers of coins minted during times of war. Therefore it was not neccessary for Republican coinage to circulate or trade at bullion value (although it may have done). Very little gold coinage was minted during the Republic. By the time of Augustus the (by now) Empire was so large that in any case, trading with states outside Rome's borders was relatively unimportant. Therefore the face values of gold and silver coins relative to bullion prices of those metals could drift off without undue problems. Note that a coin could be specified at a certain legal weight - the denarius under Nero was specified at 96 to the Roman Pound for example - but that did not neccesarily define the coin in terms of metallic value. In the Imperial period both gold and silver coins circulated at face value within the Empire. Technically speaking this was "token" money (see side panel). Silver coins were anyway, on average, underweight and the weight of surviving individual specimens vary considerably. They were also increasingly debased over time (see below), something that couldn't have been done if they were circulating at bullion value. What actually happened was that face value increased compared with bullion market price over time, so that silver coins became overvalued, perhaps by more than double. Reduction in the weight of a coin, as happened under Nero, technically at least and rather perversely, increased the overvaluation of the coin. Of course, silver was a commodity like any other, subject to the laws of supply and demand and there were no financial indices published in newspapers or on the internet. Gold coins, because they were the yardstick for the rest of the currency were only ever debased slightly, but their weight was varied from time to time. This may have been to maintain the exchange rate with silver or to prevent speculation from abroad. Such were the delights of bimetallism.

The Purpose of Minting Coins

Today we blithely talk about coins as being "issued", but what exactly did that involve?

The purpose of minting gold and silver coins in the Roman Empire (or anywhere else in the ancient world, for that matter) was to pay the government's bills, the army, the civil servants, and to build ever-grander buildings, bribing the population with the corn dole, not to mention buying the loyalty of the powerful aristocracy. Coins would also have gotten into circulation via the money-changers, as described above, with the money-changers buying coins from the mint as required. That may have been how much of the bronze coinage entered circulation.

Money for paying the bills didn't just come from newly minted coins but also from money collected by taxation, so there was a circulation of coin between the exchequer and the market, which was constantly being supplemented by new coins, so increasing the pool of money in circulation.

One of the problems of minting gold and silver coins is that you need to have a stock of those metals to do it. When times were good, supplies came from military conquests and no doubt the government owned, or at least had control of, mines. When times were bad, what then? Buying silver was an option, but only if the currency was overvalued. It would have been pointless buying silver at a price of 96 denarii to a pound when only 96 denarii could be produced from a pound.

Debasement and Gresham's Law

De-basement is the adding of base metal to silver or gold coins in order to save on expensive precious metal. In the Roman Imperial period, base metal was mainly copper, but included many other impurities including lead and iron. Another form of debasement was simply to make each coin lighter and thus smaller or thinner. Both methods were used for silver coins.

Following a period of de-basement, a further profit could be made by the mint by melting down the older purer coins. But the only way to retrieve them would be to filter them out from tax payments. However, it is likely that taxes were collected and spent at a local level by the provincial government and hence were not available to the mint. Hauling large quantities of coins safely across country just to re-mint them would not have been very appealing. For the same reason, replacing coins when a new emperor took the throne would also be difficult. However, while it is true that re-minting, say, 10 year old coins, which might be only a couple of a per cent finer than the current currency, would have been unprofitable, sorting out and re-minting 50 year old coins, which might be ten per cent finer, might have been worthwhile. There may well have been a diminution in the pool of older coins in this way, but even so coins from all periods from the Republic onwards remained in circulation right down to the middle of the 3rd century. Note that while it might have been profitable for the mint to melt down old coin, it was not profitable for the general public to do so because of the overvaluation of the coinage.

Because silver coins circulated at face value, debasement could take place without too many problems. However there was only so far that that this could be taken before disaster struck, which it did in the middle of the third century. The simplistic argument is that it was de-basement that caused the demise of the silver coinage at this time, through the workings of Gresham's Law; that people hoarded the older finer silver coins so as to melt them down for profit, until none was left in circulation. This is not quite how it happened as we shall demonstrate below.

Gresham's Law, which is of course, not a law in the legal sense, but more a set of observations on the behaviour of money in certain circumstances. Sir Thomas Gresham (1519-79) was not the first person to make these observations. They have been noted since the time of the ancient Greeks.

Gresham's Law states that "Where legal tender laws exist, bad money drives out good money". The term 'Legal tender laws' simply refers to official, state issued money and we can take it that these laws applied to imperial Roman coinage, which also must embrace the plentiful counterfeit money which circulated, even though in the strict sense it wasn't legal. In the context of the 3rd century economic meltdown, 'Good money' is taken to refer to silver coins (though Gresham's Law applies to gold coins or bronze coins or conch shells, if they are legal tender) that are not de-based, or at least not as de-based as 'bad money'. From that the definition of 'bad money' is obvious. So the Law is saying that any bad money in circulation will push the good money out of circulation, though it doesn't actually define the mechanism as to how this happens. Further explanation is required, as in the case of the Roman model, the fineness of the silver coinage was slowly diminishing throughout the first two centuries and yet there was no wholesale disappearance of the older coinage.

Simple model of circulation
The two diagrams below represent a simple model of the circulation of silver coins. The centre box represents money "in the pocket". The arrows to the box above represent the flow of taxes to the treasury and the expenditure by the state. From time to time, the taxes can be topped up by newly minted coins. The left hand box represents hoards, which can receive coins as well as "paying them out". The right hand box represents the market place. For this example the "good" money is in red and the "bad" in blue and the numbers represent millions of denarii. It is assumed that hoards contain 10% of the total money in circulation and only contains "good" money. The left-hand path can be considered as a "slow" circulation and the right-hand path a "fast" circulation

example a: Economy stable

1) The economy is stable and "bad" money circulates happily alongside the "good"

Example b: Inflationary situation

2) 400 million "bad" denarii have been put into circulation, the economy is inflationary and most of the "good" money has moved to hoards and only less than 10% of the money "in the pocket" is now "good" money.
One facet of Gresham's Law that is seldom mentioned is that provided the total amount of money in circulation is in balance with the needs of the economy, good money and bad money can circulate together.

The corollary of this is that if the amount of money in circulation is greater than the needs of the economy - what we would call inflation - then Gresham's Law tends to kick in. The main Gresham's Law 'event' occurred in the economic and military chaos of the middle of the third century, culminating in the reigns of Valerian I (253-260), Gallienus (253-268) and Claudius II (268-270). It was then that the supply of coins in circulation became greatly inflated.

It's a trait of human nature that given a choice we tend to keep objects we like and dispose of those we don't. In the case of coins we might put the nicer ones in our back pockets, and spend the poorer ones. Today, we might keep a few of those freshly minted, shiny copper pennies or spend the dirty crumpled banknote in preference to the nice crisp new one. Of course, shiny and clean, or dirty and torn, a penny is a penny, a pound is a pound, a dollar is a dollar. The choice facing Romans in the mid-3rd century was between older, finer, but still highly de-based coins and a much greater number (because of inflation) of recently minted coins. Looking back to the mid-3rd century from a modern perspective it seems obvious that people would have preferred the less de-based coins. However, the difference in the amount of de-basement between the old and the new wouldn't have been immediately obvious to the eye and there would have been no way of checking the fineness of a coin, though of course people were probably were aware that they were being de-based. This habit of holding back better coins, though, is more a perception of relative, rather than absolute value. Probably the newer coins probably started to look a bit "tacky" because of the sloppiness of their manufacture due to the pressures of minting so many coins. Eventually the decrease in size would have made them look completely worthless. Probably another factor was "sentiment". New coins were decreasing in value perhaps almost daily. Of course, so were the old, but they would have been treated with some nostalgia as representing the past. People had always hoarded coins and valuables as a sort of 'savings bank'. They were just following their normal inclinations putting aside the better looking coins, rather than deliberate cherry-picking. It didn't really require a conscious effort on the part of the population to remove silver from circulation, it was more of a slow drift of silt to the bottom of a pond. The resulting hoards may or may not have been more valuable melted down. Probably the much older silver coins were, while the more numerous and recent (and hence de-based) weren't.

Surviving hoards of this period contain large numbers of silver coins. Note the word 'surviving' though. Hoards didn't cause events, but they are a snapshot of a particular period of time. Who knows what would have happened to those hoards if they hadn't have been lost? Probably they would have been put back into circulation when their owners ran out of money or passed on, and the coins would have ended up at the mint. Of course their owners might have held on to them vaguely waiting for better times to come, and when they didn't, melted them down themselves. Probably most silver ultimately found it's way back to the mint.

We might compare the loss of silver coinage in the 3rd century, to the year 1947 when silver coins of the United Kingdom (which interestingly were of only 50% fineness, much the same as Gordian IIIs in 240 A.D.) were replaced by cupro-nickel coins. The government needed cash to help pay for war debts and silver taken out of circulation (from money paid into the banks) was pure profit for them. People noticed the change and started to put their spare silver coins into jars. By the time the silver had disappeared from circulation, scrap dealers were offering to buy these 'hoards'. Inflation was not a factor here and the price of silver was much the same in 1947 as it was in 1946. Therefore if it had been worthwhile collecting silver coins for their absolute bullion value after 'de-basement', then it would have been worthwhile before. It was simply the sudden appearance of the 'bad' money and the perceived difference in value that triggered hoarding, regardless of the profit, or even loss, in doing so. Incidentally, good silver coins turned up in circulation now and again for many more years.

Summing up: De-basement allowed increasing numbers of coins to be produced. People retained coins or spent coins according the their relative, not absolute, value in those people's eyes. Eventually, low value, high quantity, almost completely copper coins, superceded the silver. It was this that spelt the end of the silver coinage.


The following remarks apply to hoards found in Britain, although most will apply to hoards from throughout the Roman Empire.

Hoards are useful for the study of numismatics and history, but perhaps not in quite the way that many people think. Coherent groups of coins deposited together can tell us more, or at least different things than individual finds, but their importance is more on the big scale rather than at the level of an individual hoard.

Hoards are rarely found hidden near or in (old) buildings, but this may be because such hoards would be much more difficult to 'lose' in the first place. Usually they are found in open areas, and often they were originally inside a pot or bag, and sometimes with other artefacts, but that's all. Thus they cannot usually be used for dating archaeological remains.

Hoards from the early stable silver period often contain coins that cover a period of time from just a few years to, in some cases, over 200 years, stretching back to the Republic. To illustrate this, data from the book Coin Hoards of Roman Britain Volume X, has been used to complile the following table, which quantifies coins found in a not untypical hoard at Barway, Cambridgeshire. The hoard consisted of 471 coins, mainly denarii, but included 5 aurei, 1 as and 2 plated denarii.

Mark Antony32-31 BC3
Nero54-68 AD5
Galba/Otho/Vitellius68-69 AD8
Vespasian69-79 AD35
Titus79-81 AD7
Domitian81-96 AD12
Nerva96-98 AD18
Trajan98-117 AD104
Hadrian117-138 AD81
Antoninus Pius138-161 AD138
Marcus Aurelius161-180 AD56
Commodus180-192 AD3

The hoard must have been deposited (for the last time) sometime after 181 AD, the date of the most recent coin.

Minted by Mark Antony just before the Battle of Actium
"Legionary" denarius of Mark Antony,
c. 31 B.C., dedicated to Legion XXI.
The dates of these coins span a period of 150 years. Note that the largest number of coins peak in the period some 20-30 years before the most recent coin. This is because newer coins took some time to fully circulate. Similarly, the oldest coins were less likely survive the ravages of time. Nevertheless, many did. The coins of Mark Antony were of quite de-based silver which may be why they escaped melting down by the mint. Nero reduced the weight of the denarius, which would have made earlier coins attractive for melting, but all the same many coins from the Republic and Nero's predecessors did survive. As stated above, it was difficult to take coins out of circulation. Trajan did try removing some earlier coins but obviously was not entirely successful.

Had this hoard been smaller, say 47 coins instead of 471, then the older as well as the most recent coins may well have not been present. This would have led to the impression that the hoard had been deposited 20 years earlier than it may have been. It would also have appeared to have been a short term hoard, such as a hoard deposited at a time of danger or even a lost purse. Clearly, the larger the hoard, the more accurately it's nature can be determined. Archaeologists and numismatists use the terms "circulation hoards" and "savings hoards" to describe these apparent short-term and long-term hoards, but it is now recognised that it is difficult to differentiate between the two and so both types of hoards tend to be treated as "savings hoards".

How do we explain the wide range of dates in this and other hoards? Clearly it is unlikely that the hoard was built up over a period of 150 years, not the least because Britain was not yet Roman in 31 BC. As outlined above, the main opportunity for removing coins from circulation was by the mint melting them down. But the only way to do this was via taxation payments. Taxes were collected at local level, often by 'tax farmers' who may have paid the taxes wholesale in gold. These would have been accepted by the local government and mainly used to fund local 'services'. Any surplus due to the central government was probably paid in gold or even in "letters of credit" and so the chances of silver coins returning to the mint were slim. In any case, they would have had a long way to travel as there were only a few mints. De-monetisation by decree would also be unsatisfactory as coins that have an intrinsic value tend to remain acceptable whatever the official policy. Some coins may have been removed by the mint, some may have simply worn out; early bronze coins that have worn almost flat and countermarked for re-use are often found. At any rate coins remained in circulation for a long time. We can consider hoards as being part of the circulation, albeit a "slow" part, since people tend to save money in order to be able to spend it later. People may have had a preference as to what they kept in their hoards -shiny new coins, Republican coins maybe. Possibly certain coins stayed longer in hoards than others. There is no way of knowing. We can also never know how long an individual hoard had been built up before it was last buried, but it is doubtful that it would have been more than one person's lifetime. If it had been, say 20 years, then all the coins in that hoard would have been in circulation "in the market place" within the last 20 years. People save money with the ultimate intention of spending it, so it is certain that people retrieved from their hoards, as well as depositing it. Hoards may have been "accessed" once a day, once a month or once a year, we just don't know. It is likely that the older the coins within a hoard, the longer they remained in that hoard and that they only occasionally appeared in circulation, rather as Victoria Bun Pennies sometimes appeared in change in pre-decimal England. All the same, all the coins represented in a hoard were to some extent in circulation at the time of deposition of the hoard.

The reasons for individual hoards being deposited and the reasons for their loss can almost never be known. However, that hasn't stopped speculation, especially when a spectacular hoard comes to the attention of the popular press! Much information can be gleaned from the pattern of a number of hoards. Here are some examples of what can be learned and what are misconceptions:

  • A number of hoards from one area and at a particular time often correlate with military action or civil disturbance. However, it is easy to draw the wrong conclusions. For example hoards connected with military activity in a particular area, may lead to the conclusion that people were hiding their valuables in the face of some threat, when what is in fact being highlighted is that extra money that was being imported into the area to pay the armies and to pay for supplies such as food, horses, weapons, etc., that an army needs. Such sums could not be immediately spent and so were hidden away. A cessation of hoards at exactly the same time might indicate the elimination or migration of the local population, but which also might lead to the possibly erroneous conclusion that a larger number of hoards than usual were being deposited.

  • From the end of the 3rd century, the political and economic situation was chaotic. Various emperors and usurpers were vying for power. The hoard evidence reflects this and sometimes conclusions can be reached about what was happening at the time. It seems, though, that just as one conclusion is being drawn, another hoard turns up that contradicts those conclusions.

  • In 410, the Emperor Honorius cast his British province adrift. In fact supplies to Britain of bronze and silver coins ceased in 402 and gold in 406. Naturally the terminal dates of hoards in Britain (with a couple of interesting exceptions) are no later than 410. This inevitably leads to any find being dubbed as being "hidden from Saxon invaders". Although there are some finds that could be put in this category, such as the great Hoxne hoard, there is no evidence that the majority of hoards were hidden for this reason. In fact as no coin can be dated beyond 406, there is no reason why hoards could not have been deposited much later than 410 and that coins were still in circulation well into the "dark ages".

  • The debasement and ultimate demise of the silver coinage in the middle of the 3rd century is often laid at the doors of hoarders. No doubt that is the impression that the government of the day wanted to give. Up until that point, the slow debasement of the silver currency had little effect since coins were circulating at face value. From the middle of the 3rd century, hoard records show that silver was disappearing from circulation, but what cannot be proved is that silver coins were being hoarded for any other reason than the normal desire to hide away money and valuables surplus to everyday requirements. It should also be remembered that the hoards found today are only the ones that were lost. Other hoards that weren't lost were, by definition, disposed of one way or another. If the government had had any sense it would have grabbed the good silver coins before anyone realised what was happening. It may well have demanded tax in good silver which would have to had to have been taken from supplies in hoards. Possibly this was one of the reasons for the number of new mints opened around the Empire

    Coins of Gordian III, 238-244, a few years before the big crash, are very common and are usually in unworn condition, and are often cited as evidence for them being collected for melting down. What the evidence actually shows is that Gordian's coins are numerous because of inflation and because they were the most recent before the removal of silver from the currency, and that they are unworn because they were not in circulation long enough to become worn.

Beginning of coinage in Republican Rome

Rome was a bit later than most ancient states in adopting coinage. The first units of currency were lumps of unmarked bronze known as Aes Rude followed by marked bars of bronze called Aes Signatum. Large round bronze coins, known as Aes Grave were made around 280 BC. These were initially so large that their value must have been based on their metallic content.

The first silver coins were copies of the coins of the Greek colonies that surrounded Rome in Italy. The silver denarius was not minted until c. 211 B.C. Gold coins were only rarely minted.

During the Republican period the economy only slowly became monetised, large amounts of coin being issued during periods of unrest, such as the 'Social War', 90-88 B.C.

Imperial coinage- 27 B.C. on

The first emperor, Augustus (27 B.C. to 14 A.D.) reformed what had been the Republican currency during his reign. The main denominations were:

Gold Aureus, = 25 Denarii
Silver denarius = 4 Sestertii
Orichalcum (an alloy like brass) Sestertius = 2 Dupondii
Orichalcum Dupodius = 2 Copper Asses
Copper As = 2 Semis
Copper Semis = 2 Quadrans
Copper Quadrans

The gold aureus was produced at 40 to the Roman Pound (322.5 grams), more or less, the average weight being 7.75 gms. The silver denarius was minted at 80 to the Roman Pound, or 3.89 gms

Today, in the UK for example, we tend to think of the Penny as fraction of a Pound; i.e. one Pound as being divided into 100 pence. With the Roman currency, it is more the case that a denarius was a multiple of the sestertius and the aureus a multiple of both. It can be argued that bronze coins (sestertii and below) were token coins because they were not based on their metallic value. However, the bronzes were not small change. The daily pay for a worker at the beginning of the period may have been about one denarius, so a sestertius represented a quarter of a day's pay. Surviving writings, at least from the early period, usually give prices in sestertii, even if the numbers run to millions.

The emperor's head on the dupondius was usually, but not always, depicted with a 'radiate' crown. Since the dupondius equalled 2 asses, this is taken to mean that a radiate head meant 'double something'. This logic seems to have applied to many of the denominations that followed, but not all, and it may just have been a distinguishing mark to show a difference with the denominations above and below.

Examples of five denominations
(1) denarius of Trajan, 98-117 (RIC 212) (2) sestertius of Trajan (RIC 552 var)
(3) dupondius of Trajan, 98-117 (RIC 676) (4) as of Nero, 54-68 (RIC 312) (5) quadrans of Trajan (RIC 692)

The first two centuries of the Imperial era remained economically stable. The purity of the silver drifted down somewhat although it also went up sometimes. The weight of the denarius, which had been struck at 84 to the Roman Pound was reduced to 96 to the Pound under Nero (54-68 A.D.) and the weight of the gold aureus to 45 to the Pound.

The fineness of the silver denarius was still approximately 83% in the reign of Antoninus Pius (138-161). The weight varied slightly over this time but on average not by very much. Note that figures for fineness and weight given in text books look deceptively accurate because the figures are simply averages of a number of coins. In fact there are wide differences between individual coins and issues. This may be explained by the fact that:

  • The ancient methods of processing molten metal tended to give a non-homogenous mix.
  • Different batches of metal were made with roughly weighed amounts of the appropriate metals and varied one batch to another.
  • The debasement wasn't planned as we might like to think, but was simply a case adding a bit more base metal when supplies of silver became tight.

An ancient forgery
A fouree (plated) denarius nominally of Domitian as Caesar, 69-79 with a reverse of his father, Vespasian. Note the brown and green copper core showing through.
During the whole silver period, right from the days of the Republic, forgeries of silver coins were abundant (more abundant than is realised because forgeries tend to be distained by collectors and numismatists). These forgeries, known as fourees, were made from copper flans plated with a thin coating of silver and when new must have looked like the real thing.

From the reign of Septimius Severus (193 - 211) things started to go downhill. Severus had managed to gain the ascendancy after the death of Commodus but needed the support of a large army to do it. This resulted in further debasement of the denarius (56%) and a large increase in the money supply in order to pay the army.

His son, Caracalla (212 - 217) introduced a new coin, called by modern scholars, the antoninianus (often called a 'radiate', because of the radiate crown on the emperor's head). This coin was one and a half times the weight of the denarius, of similar purity, and a commensurate diameter, and is believed to have been worth two denarii (because the radiate head is believed to signify double). However, the denarius continued to be minted. In fact the antoninianus didn't take off straight away as it was discontinued after the death of Caracalla and not re-started until the reigns of Balbinus, Pupienus and Gordian III (238 - 244). Even then the denarius continued in production, production only tailing off in Gordian's reign. The fact that these two denominations existed side by side, show that they circulated at face value.

  Antoninianus and denarius circulated together  
(1) antoninianus (RIC 284a) and (2) denarius (RIC 231) of Caracalla, 198-217
(3) antoninianus (RIC 95) and (2) denarius (RIC 127) of Gordian III, 238-244
These two denominations are distinguished not just by size, but also of the radiate crown worn by the emperor on the antoninianus

Probably not coincidentally, a gold double aureus, also called a binio was introduced under Caracalla and in the same way the antoninianus was one and a half times the weight of the denarius, so it's weight was one and a half times the weight of an aureus, and like the antoninianus the binio also featured a radiate crown. This also indicated that gold coins circulated at face value and were overvalued with respect to the price of gold. This last point is important since the gold was pure and the users of gold coins, being more sophisticated, would have appreciated the profit to be made had the coins been undervalued.

By the reign of Gordian III the fineness of silver coins had dropped to 48%. Note that even at 48% fineness the coins of Gordian still looked silver.

Crisis, 244 - 270 A.D.

The reign of Philip I (244-249 AD) ushered in a period of rule by emperors who were mainly opportunist army commanders that had seized power by revolt or assassination. They were, though, at the mercy of the armies they commanded. This required more money to pay them, which in turn led to inflation and further de-basement of the silver coinage.

Silver disappears from the Antoninianus
The decline of the antoninianus:
(1) Philip I, 244-249 (RIC 58)
(2) Gallienus, 253-268 (RIC 555)
(3) Claudius II, 268-270 (RIC 14)

The fineness of the silver coinage (by now mainly antoniniani) went through the floor from Philip I (47%) to Claudius II (268-270) (2%), much of the drop taking place during the reigns of Valerian I and his brother, Galienus (253-260), so that newly minted coins no longer looked silver. Inflation which had been increasing since the time of Septimius Severus, was now rampant. The conditions were now in place for Gresham's Law to come into effect. There was a much larger money supply than was needed and the newer coins not only were 'bad' but looked bad. By 270 good silver coins had been removed from circulation by means of the mechanism described above.

The hoard evidence reflects these events with hoards of mainly silver coins petering out and hoards of debased coins starting to appear. It's important to realise that when looking at the overall hoard record, that although silver coins disappear during this period, there is no hard cut-off; silver and base-metal coins appear alongside one another over a period of many years. Of course, there is more than one interpretation of this. Perhaps some people weren't bothered about whether they were saving 'good' or 'bad' coins. Perhaps the silver coins 'ran-out' and the hoarder had to make do with the 'bad' coins. We also don't know if the treasury was removing silver from circulation before it had a chance to be hoarded, maybe even requiring people to pay taxes with good silver coin.

Although an attempt was made to make the new silver-deficient coins look silver by coating them with a thin layer of silver, it was already too late as inflation had already taken hold. In any case the pressure of minting such a vast quantity of coins meant that they were small and poorly manufactured. We can imagine that as prices went higher and higher and the value of the antoninianus lower and lower, that the diminishing fabric of the coin appeared to track it's value.

Bad though the effects of inflation were (high prices etc.), the problems went further than that. As the value of the silver coins decreased, if individuals had been allowed to buy gold coin at the official price, they would have had a very good bargain and would have led to wholesale purchase of gold coins. Therefore the rate of exchange at the money-changers between the antoninianus/denarius and the aureus must have rocketed. This would have made it very difficult to carry out normal trade. The bimetallic system had truly created two separate economies.

Altering the weight of the gold coins may have seemed one way to get round this and during the crisis period the weight of gold coins seems to have been very erratic, but eventually the authorities decided that they might as well have at least one stable currency and stabilised the weight of the aureus at 1/60th of a Roman Pound.

The Double Sestertius

From this point on, the reasons for minting particular coins and the relationship between one denomination and another becomes confusing, to say the least. So let us examine the first of these anomalies.

Trajan Decius (249-51) introduced a coin that has been dubbed a double sestertius. This is because the weight and size was much greater (though perhaps not double) than a standard sestertius and the fact that the emperor's head was radiate, though as stated above, it is possible that this feature was just meant to differentiate it from other denominations.

A double sestertius, if that was what it was, would have been equivalent to half a denarius or a quarter of an antoninianus. That seems a somewhat unnecessary denomination in view of the fact that the currency was going through the floor. So what was going on?

Last of the big bronzes
After the initial issues, the double sestertius was reduced in size, this one being approximately the size and weight of the old sestertius. Postumus, 260-269 (RIC 143).
Note the radiate crown on the obverse.

As we have seen, the rate of exchange of the denarius and the antoninianus with the aureus must have increased dramatically. We would assume that the sestertius if it had have been a simple token coin, would track these changes. However, during the silver currency's tribulations, the sestertius had remained at full size (diameter), even though the weight had decreased somewhat. The sestertius was still a magnificent coin and had never been considered 'small change'. The price of everything, in terms of antoniniani, had been going up and that must have included the price of bronze bullion. Some consider that this indicates that because the value of the metal in the sestertius was now worth more than the (mainly bronze) metal in the antoninianus that the sestertius circulated at a premium. I may be that it had simply become the prefered medium of exchange in the market-place. Whatever the case the coin was obviously perceived to still have a high value and perception was everything. A coin was worth whatever people were prepared to exchange it for.

Presumably the aim of Decius was to capitalise on the stability of the sestertius by introducing the double sestertius which then made it equivalent to half of what the denarius should have been (i.e. 50 to the aureus), as replacement for the antoninainus/denarius which were sinking fast . Possibly inspiration may have come from the large medallions that had often been distributed at the New Year celebrations. They were not intended for circulation, but when the novelty had worn off they may well have been spent, maybe as a double sestertius. Whatever the intention, the experiment didn't last long. The Gallic emperor Postumus (259-268) also tried out a double sestertius, but it was apparently soon debased as the size of the coin contracted to the size of a normal sestertius and even smaller so that it was difficult to differentiate it from the radiate dupondii.

The Aftermath

By 270, the monetary system was a complete shambles. Enter Aurelian (270-275). Aurelian introduced an improved antoninianus, with a restored weight and size, containing 4% silver with a much improved fabric. Some of these antoniniani had the legend "XXI" at the bottom of their reverse (the "exergue"). Some, possibly all, of these two types were silver washed. It's not possible to tell which were, because of the tendency for coins to lose their silver wash while in the ground.

The most widely held theory concerning the "XXI" mark is that it represented twenty parts of base-metal to one part of silver, a theory re-enforced by a rare coin of Tacitus with the legend "XI" (ten to one) and containing double the amount of silver. These coins inscribed "XI" are believed by some to be a double antoninianus, the mark being a mark of denomination. To use "XXI" or "XI" as a mark of value seems somewhat obtuse, especially as coins with and without "XXI" and of the same size and fabric were produced at the same time. Clearly it was felt that de-basement had undermined public confidence and possibly the "XXI" marks were intended to advertise the soundness of the new denominations, rather than as a mark of value. Aurelian also produced a smaller coin with a similar silver content with a laureate bust, which has been dubbed a denarius, though we don't know if this name was still used for this coin.

  Aurelian's new coins  
(1) "aurelianus" of Aurelian, 270-275 (RIC Rome 65), (2) "antoninianus" of Aurelian (RIC Milan 128)
(3) "double aurelianus" of Tacitus, 275-276 (RIC 214)
Note the "XXI" on the reverse of the aurelianus, and the "IA" (Greek for "XI") on the reverse of the double aurelianus.

The purpose of the new system was of course, to stabilise the economy. No doubt the new coin was tariffed at a fixed rate to the aureus, although we do not know what that rate was. So how did the new antoniniani relate to the old? To have tied the old to the new at a fixed rate would have been counter-productive, like tying up alongside a sinking ship. It seems that the old coins were de-monetized. Whether they were bought up at an exorbitantly poor rate, or just left to circulate at a local level, until they died out naturally, is uncertain.

Inflation had made much greater demands on the mints and the soldier-emperors needed to get cash to where their armies were. Aurelian carried on where his predecessors had left off by opening more mints around the Empire to facilitate these requirements. Soon the long established provincial eastern coinage would be dispensed of.

Reforms of Diocletian and after

A downloadable Excel spreadsheet showing a time-line of late Roman denominations is available click here

Apparently Aurelian's reforms weren't one hundred per cent successful, because around 294 Diocletian (284-305) decided to throw everything out and start again, apart from the gold aureus. He introduce a large copper coin, weighing in at 10gms known as a follis. It was struck with a laureate head rather than a radiate one, contained about 3% silver and some, if not all, were silvered on the outside. (One of the mysteries of the late Roman coinage is why they persisted adding silver to base metal coins when nobody could have known it was there.) Undoubtedly it was tied to the aureus, but what the exchange rate was can only be guessed at (and many have!). Most of the new names for denominations from now on have been invented or at least assigned in modern times as the actual names are unknown.

Coins of the Tetrarchs
(1) follis of Diocletian, 284-305 (RIC Alexandria unlisted)
(2) Post-reform antoninianus of Maximianus, 286-305 (RIC Cyzicus 156)
(3) Quarter follis of Maximianus (RIC Siscia 146)
(4) argenteus of Constantius I, 305-306 (RIC Rome 42a)

All the surviving fractional coins, such as the as and the semis as well as the denarius (which had declined as the antoninianus had) were discontinued. However, the new follis spawned some rather strange fractions. Some were obviously smaller versions of their bigger brother, but some seem to be unconnected by weight, and from 1700 years later it's difficult to see how people of the day could understand what their value was intended to be. Radiate coins (known as "post-reform radiates") were also continued for some 5 years (but with no silver content) and again it is difficult to see where they fitted in.

At the same time Diocletian introduced a silver coin, known as the argenteus or siliqua. This coin was made with reasonably fine silver and was the same weight as the old denarius. Whether the exchange rate with the aureus was the same as before is not known.

Around 301 A.D. Diocletian introduced his "Edict of Maximum Prices". This was an attempt to further stabilise the economy by laying down maximum prices for goods and official wage rates for workers, though the attempt was pretty futile. However, the Edict is an indication of the concern felt by the government about the stability of the economy and monetary system.

By the reigns of Constantine I (306-337) and Licinius I (308-324), the size of the follis was plummeting, so that by the end of Constantine's reign it weighed only about 3 grams as compared to 10 grams when it started. Whether this was a deliberate debasement or whether despite all attempts at stabilisation the denomination continued to fall in value and the authorities were trying to 'match' size with value, is not known. At any rate, early large folles found today are usually fairly un-worn, a sure sign that they weren't in circulation for very long.

  Reduced follis - centenionalis  
(1) Reduced follis of Constantine I, 307-337 (Aug) (RIC Lugdunum 219)
(2) Reduced follis of Licinius I, 308-324 (RIC Arles 196)
(3) Well-silvered AE3 of Constantine II, 317-337 (Caes) (RIC Siscia 163).
This is really the same coin as the reduced follis, but is now often called a centenionalis.

Gresham's Law doesn't just apply to precious metal coins, it can apply to any legal tender, including bronze. It may be that the ups and downs of the bronze and billon coinage in the 4th century can be seen as another manifestation of that law, but the evidence is so confusing that it is difficult to make that judgement.

Constantine re-invented the aureus by introducing a new gold coin, called the solidus, weighing 1/72 of a Roman Pound (c. 4.5 grams). This standard remained stable into Byzantine times and carried on into the Muslim world as a dinar. The solidus seems to have circulated at bullion value which would account for it's consistent weight. This also implies that transactions took place by weighing the coins.

  solidus and siliqua  
(1) solidus of Honorius, 393-423 (RIC Constantinople 24 var)
(2) siliqua of Valentinian II, 375-392 (RIC Aquileia 15d).

Although minting of Diocletian's silver argenteus was discontinued after his death, Constantine minted a few obscure silver coins of various weights, but towards the end of his reign (or perhaps by his sons after his death) he re-introduced the argenteus (now universally called the siliqua). The other main silver coin introduced was called the miliarense. Going by the weight of these two coins the siliqua would have been worth three-quarters of a miliarense. An odd ratio, but then many odd fractions and multiples of these coins were subsequently introduced so that they have been given names such as 'reduced half siliqua' and 'heavy miliarense'. But at least a stable silver currency had been achieved which lasted to the end of the western Empire, even though the volume of coins was much lower than in the heyday of the Empire.

The base-metal reduced follis continued under Constantine's sons and at some stage metamorphosed into a coin known as a centenionalis. (centenionalis is a real name, but which denominations it applied to is a matter of debate). In 348 the base-metal coinage was revised and three new types emerged (FEL TEMP types); a large centenionalis (c. 5.25 grams (3% silver), a small centenionalis (c. 4.25 grams, 1.5% silver) and a half centenionalis (c. 2.4 grams, 0.4% silver). The average weight for these coins belies the fact that in practise the weights of individual coins varied enormously. This coupled with the fact that Constantine's sons were squabbling with one another for possession of the Empire and the localising effect that debasement had had, means that quite possibly the first two of these coins were actually the same denomination. Again, possibly, with silver and gold coins now available, perhaps these debased coins were no longer tied to anything and simply formed separate local currency pools.

Reforms of 348
(1) Large centenionalis of Constantius II, 337-361 (Aug) (RIC Alexandria 72) (7.4 gms)
(2) Large centenionalis of Constantius Gallus, 351-354 (RIC Alexandria 74) (6.3 gms)
(3) Small centenionalis of Constans, 337-350 (Aug) (RIC Constantinople 88) (4.2 gms)
(4) Half-centenionalis of Constans (RIC Siscia 241) (1.9 gms)
These coins were all issued between 348-355, but note the varying weights of the first two.

At this point, the base metal coins become mainly a token coinage with no silver content at all. A couple of attempts at re-introducing large impressive bronze coins are worthy of note. Magnentius, usurper in northern Europe and Britain, produced a large, so-called, double-centenionalis, with a prominent Christian symbol. There is speculation that this might have been because he had no access to silver to produce any silver coins. A few years later, Julian II (the "Apostate") produced another large coin showing his unashamed pagan leanings.

Also called Maiorinae
(1) AE1 of Magnentius, 350-353 (RIC Trier 318) (7 gms).
(2) AE1 of Julian II, 360-363 (RIC Heraclea 103) (8.9 gms).

The values and functions of most late Roman denominations are lost in the mists of time and any attempt to explain them in this short article would be fruitless. The hoards from the 4th century contain enormous numbers of bronze coins, so clearly inflation wasn't quite licked. Bronze coins in the 5th century became smaller and less numerous, indicating the increasingly low status of the bottom strata of society and the return to barter as a means of exchange as the Western Empire came to an end. Silver coinage continued in a much smaller volume than in the hey-day of the denarius, but at least there was no attempt to de-base it -perhaps the lessons had been learnt. As stated above, the gold solidus (and it's rare fractions) continued. Constantine, as well as converting the Empire to Christianity, had moved his capital to Constantinople and with it the balance of power. The Roman Empire was to continue in the east for 1000 years after the fall of the western empire, to become known as Byzantium. The Roman system of money continued until the reign of Anastasius I (491-518), which is considered to be the start of the Byzantine period for numismatic purposes.


siliqua of Magnus Maximus, RIC Trier 84b

As related above, the last of the Roman coinage had reached Britain's shores by 410 AD. Many of the silver coins (siliquae and miliarense) found in Britain from this period (and mostly only Britain) have been "clipped"; that is to say, a thin strip of silver has been cut from the circumference of the coin. The profit to be made by doing this is obvious, but who did it? Suggestions have been that it was done by the authorities (in Britain), by the local population, or even that coins were reduced in size to match continental Visigothic and Vandalic issues as late as 440 AD. Whatever the answer is, it would suggest that silver coins were still circulating at face value.

Useful Book and Web References

Uses and Abuses of Gresham's Law in the History of Money by Dr. Robert A. Mundell, 1999 Nobel Laureate

Money and the Mechanism of Exchange by William Stanley Jevons 1875

Roman Coinage in Britain by P.J. Casey, Shire Archaeology, ISBN 0-7478-0231-9

Romano-British Hoards by Richard Anthony Abdy, Shire Archaeology, ISBN 0-7478-0532-6

Coin Hoards from Roman Britain Volume X edited by Roger Bland and John Orna-Ornstein, B.M. Press, ISBN 0-7141-0887-1

Edict of Diocletian

Coinage in the roman Economy by Kenneth W. Harl. John Hopkins University Press 1996 ISBN 0-8018-5291-9

Coinage in the Roman World by Andrew Burnett, Spink 1987 ISBN 0-900652-85-3

Roman Imperial Coinage Volumes I-X by various authors, Spink -used as reference for above photos (RIC)

A downloadable Excel spreadsheet showing a Time-line of Roman rulers

A downloadable Excel spreadsheet showing a Time-line of late Roman denominations

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