Although it is hazardous to generalize about anything concerning ancient Greek coinage, we will discuss a dozen basic concepts in general terms. Clearly, these concepts do not apply to every coin issue of the ancient Greeks, but they will apply in most cases, and thus are useful to revisit.
The Origins of Coinage: How coinage functioned once its economic role had been established is fairly well understood, but the purpose of the very first ‘coins’ may have been quite different. After all, people had survived for millennia before without any coins at all, so why the sudden emergence of coinage?
Though we can only speculate about why coins were created, scholars generally agree that it may not initially have been to facilitate everyday commerce. The earliest ‘coins’ may have been created for use in governmental transactions, such as the payment of mercenaries, inter-governmental transfers, or, perhaps, as a medium for taxation.
It is possible that they were introduced by private bankers or bullion agents for use within their own profession. The great variety of designs and the appearance of personal names on some early electrum suggests that powerful individuals may have produced coins with their own emblems. Without literary evidence, it is doubtful that the truth can be revealed on the numismatic evidence alone.
Art versus Commercial Success: The most successful trade currencies of the ancient world were – in general – those which maintained established designs, or those which copied the designs of other such currencies. Examples of the former include the coins of Syracuse, Carthage, Athens, Aegina, Corinth, Tyre, and the Persian kings, and the latter would include the many later copies of the original coin types of Philip II and Alexander III of Macedon, Lysimachus of Thrace, and the venerable Athenian ‘owls’ and Corinthian ‘colts’.
Even Greek kings and Roman emperors, who mainly issued portrait coins, used a standard formula for their coin designs. Despite the great variety within, most coins of these monarchs adhere to the predictable and familiar combination of a portrait on the obverse and an often variable design on the reverse.
Greek bronzes, which often boast a wide range of types, are a bird of a different feather. Among precious metal coins, the electrum of Cyzicus, Phocaea and Mytilene are notable exceptions: even though their designs may have changed virtually every year, all three of these were wildly successful within their own spheres of circulation. However, Classical-period electrum breaks many ‘rules’ of coinage, so this is no great surprise; in their case the consistent element is not the design, but the distinctive physical form and the issuing authority.
Size and Function: The greater the intrinsic value a coin possessed, the more likely it was to be used for trade and export; likewise, the lower the intrinsic value of a coin, the greater the likelihood it was used for local transactions. Whether it was a modest issue suitable only for regional trade, or a truly ‘international currency’ destined for the four corners of the Mediterranean world, larger coins still were generally struck to facilitate trade. At the other end of the spectrum, copper-based coins had little or no buying power outside of their place of origin. A comparison can be made to modern times: it is hard to imagine a merchant in Bolivia accepting a U.S. quarter-dollar for a purchase, even if it is worth more than the item being purchased, but that same merchant would probably consider accepting a U.S. $100 bill if the circumstances are reasonable.
Weight Standards: It would appear that all ancient precious metal coins were struck to a weight standard. Many different weight standards co-existed in the ancient world, so when a coin of a ‘foreign’ standard was used in trade it presumably was thrown on a scale and valued with its intrinsic value as the guide. But if it was a popular weight standard (such as that of Athens), merchants in distant lands might be more forgiving because they could use it when making purchases of their own.
Denominations: The overwhelming majority of ancient coins had no indication of denomination in the design or the inscription. Fortunately, precious metal coins were struck to specific weights within a weight standard, the result being a denomination. Since the weights of precious metals were regulated, denominations for these issues can usually be determined on the basis of weight alone.
This orderly system of weights allowed for easy conversions at their place of origin. Some denominations (such as drachms, staters, assaria, denarii and sestertii) were the actual terms used by the ancients, whereas others (such as post-reform radiates, quadrigati or victoriati) are inventions of modern scholarship. Copper-based coinage presents a host of problems because the weight was not closely regulated. As a result, the denominations are almost always unknown, and they are usually described based upon their diameter. Some coppers, however, are marked with pellets or bars which indicate their denomination.
Gold-to-Silver Ratio: The value of gold and silver relative to each other was important even in ancient times. Alexander the Great stabilized the ratio from its earlier ratio of about 13:1 to 10:1, which made five of his Attic-weight tetradrachms equal to one of his Attic-weight gold staters. But over time, normal economic pressures, changes in consumption rates, or a new find of either metal, caused this figure to fluctuate.
In this bimetallic partnership, the gold coinages generally maintained their purity and weight, whereas the silver coins were prone to adjustments in weight or purity to compensate for temporary changes in the relative values of the metals.
Metamorphosis of Fabric: From the late 7th Century to the late 1st Century B.C. there was a gradual transformation in the ‘fabric’ (the physical characteristics of the planchets and the dies used to produce coins) of Greek coins from narrow-and-thick to broad-and-thin.
Archaic coins were typically struck on thick planchets with relatively high-relief obverse dies and deeply-cut reverse punches or dies. By the late Archaic period and the early Classical period, this had largely given way to slightly broader planchets struck by dies with fully realized designs in relief on both sides. The trend continued into the Hellenistic times, characterized by coins of relatively low relief that were struck on broad, thin planchets. There are regional variances which contradict this evolution, but it applies to the majority of Greek coins.
Development of Style: Though in most cases the style of a series of coinsoften was refined with the passage of time, this was not always the case. In other words, the ‘crudest’ coins within a series are not always the earliest ones. A good example is the Athenian ‘owl’: the earliest tetradrachms struck prior to 500 B.C. are of markedly finer style than the later issues of about 480 B.C. which seem to have been hammered out for the invasion of Xerxes. The style of the owls ‘recovered’ at least by 465 B.C., and the trend reversed. The quality of workmanship evolved for the next two centuries in the more typical direction of gradual artistic decline.
Each region developed at its own pace, and not all followed in the footsteps of Athens. Thus, it is especially treacherous to date any Greek coin based on its similarity to coins of an unrelated series. That’s not to say stylistic comparisons are useless, just that they must be approached with caution. Many Classical and Hellenistic coins of Etruria, Northern Greece, Crete, the Bosporus, Cyprus and Phoenicia are similar in style and minting characteristics to typical Greek coins of the Archaic period, and only hoard evidence has prompted scholars to ‘down-date’ these Archaic looking coins to the later times.
Beware of Style: The vast majority of Greek coins do not bear dates of any kind, and they must be dated by evidence drawn from careful study (interpretation of hoard evidence, overstrikes, metrological data, die studies, etc.) and from the more subjective realm of style. Style would include the content of the design, how it is engraved, and to a certain degree, the physical characteristics (fabric) of the coin.
Designs sometimes were deliberately archaized, either to maintain a popular design for commercial benefits, or simply for regional esthetics. Certain mints in Northern Greece, such as Acanthus, embraced an Orientalizing trend in art for a rather significant period of its coinage. All of this demands that numismatists have an open mind when it comes to assigning dates to Greek coinage.
Dates on Coins: It is true that some ancient Greek coins (and many Roman coins) bear dates, but they are not the literal dates that appear on modern coins. Instead they are reckoned according to eras, which are anchored to a historical event or milestone, such as the foundation date of a city, the date a city or empire gained (or re-gained) its freedom from an occupying force, or the beginning a monarch’s reign.
Dates typically are expressed in letters from alphabetic systems, in with each letter has been assigned a numerical value. Only two pieces of information are necessary to ‘translate’ such dates: the date when the era began and the numerical equivalent of the letter(s). The lack of either piece of the puzzle renders the ‘date’ on the coin virtually useless beyond, perhaps, establishing an internal sequence.
Portraiture and Propaganda: No portrait that appears on ancient coinage is entirely faithful. Even in the most brutally realistic portraits we must presume there was some element of fiction because the main function of royal portraiture was to make a political statement, hopefully while still resembling the person portrayed, and often times it would seem that an effort was made to flatter the monarch.
The most severe examples of idealization occur under some portraits of later Hellenistic kings, and during the late Roman and the Byzantine Empires. Topping the list may be Mithradates VI of Pontus, with his windswept, youthful, god-like portraits. But at least his portraits are lofty in their art. The later Roman portraits, starting in the late 3rd Century and continuing into the Byzantine era, often are mere caricatures. The intention was to demonstrate abstract attributes, such as solidarity, piety, strength and religious enlightenment, not to show the individualized features of the emperor or empress.
Production versus Survival: The number of dies used to produce an issue of coinage varied greatly, and it is generally assumed that the greater the number of dies, the larger the issue. A coinage for which 300 different dies have been documented must have resulted in far more coins than one for which only a dozen dies are recorded. But survival rates for coins do not always match the apparent size of the issue, as much of it boils down to unpredictable circumstances.
Some of the factors relate to ancient practices: were most of the coins melted in ancient times? Were they recalled by the issuer? Alternatively, is a relatively small issue over-represented by lucky discoveries in modern times? The list of factors that affect survival rates is extensive.
A perfect illustration occurs in Sicily with the first tetradrachm issues of the neighboring cities Naxos and Catana. Only one pair of dies was used at Naxos, yet nearly one hundred (or more) examples survive. Compare this with the more extensive first series of tetradrachms issued at Catana, for which more than twenty dies are known: despite the greater number of dies employed at Catana, the combined population of that city’s early tetradrachms may be lower than that of Naxos with its single set of dies. Clearly other factors have affected the survival rates in this case.