Early in the third century A.D. the Roman Empire entered into a
period of military anarchy that caused great economic stress.
Coinage fell victim to spiraling inflation and large quantities of
coins were buried as a result. This grave misfortune has translated to
a bounty for today’s numismatists, as the burial of so many treasures
has made coins of this era among the most commonly available.
In this period gold coins often were struck at reduced weights and
the value of silver coinage dropped through the effect of reductions
in purity and weight.
By this time the silver denarius had been Rome’s principal silver
coin for almost 450 years. It ceased to be struck under the emperor
Gordian III (who reigned from A.D. 238 to 244) and was replaced by a
relatively new coin, the double-denarius, which had been introduced in
215 by the Emperor Caracalla (A.D. 198 to 217).
Nowhere is it recorded why the double-denarius was introduced,
though it may have been in an attempt to stretch resources. It is
believed that the new coin was officially valued at two denarii since
it bears the hallmarks of a double-denomination: male portraits are
adorned with a radiate crown and female busts rest upon a crescent moon.
Averaging about 5.10 grams when it was introduced, the
double-denarius had the silver content of only 1.5 denarii, as that
denomination typically weighed about 3 to 3.4 grams. Since both coins
were of similar purity (about 50 percent in this period), the new
double-denarius appears to have been overvalued in relation to the
denarius, perhaps to help compensate for Caracalla’s hike in legionary salaries.
The weights of coins on a piece-to-piece basis varied
considerably. A quick survey of 50 double-denarii of Caracalla
included coins ranging from 4.13 to 6.1 grams; an equally random
sampling of 50 denarii from the year of Caracalla’s reform yielded a
range of 2.67 to 3.62 grams.
The ancient name of the double-denarius is uncertain. Today it is
best known as an antoninianus since a reference to argentei
antoniniani in the Historia Augusta refers to Caracalla’s new
double-denarius. Though that may have been what they were called when
that work was composed, Historia Augusta is deeply flawed and was
composed long after the use of the coin — sometime between A.D. 360
and 425 — so this information must be considered questionable.
Caracalla struck double-denarii up until his murder in April, 217.
The denomination was then issued by his successor, Macrinus (217 to
218), and also by the next emperor, Elagabalus (218 to 222), who for
unknown reasons appears to have ended the coin’ production in 219. The
next two emperors, Severus Alexander (222 to 235) and Maximinus I
“Thrax” (235 to 238), did not strike double-denarii.
The double-denarius was reintroduced in 238, a year of violent
revolution. Three of the six emperors who reigned during that year
struck this denomination, with the last of them, Gordian III (238 to
244), doing so on a large scale.
Gordian’s pattern of silver coinage was odd, suggesting the
implementation of at least two changes in his monetary policy. From
238 to 241 he almost exclusively struck double-denarii, then, from 241
to 243 he issued both denarii and double-denarii, and from 243 to 244
After Gordian ceased production of denarii in 243, that
denomination was rarely struck again. With one notable exception,
later denarii all appear to have been ceremonial pieces. The
double-denarius had now become the standard silver coin of the realm,
and would remain so for the next three decades.
However, soon after achieving its supremacy, the quality of the
double-denarius began to fall precipitously both in silver content and
production quality. Early in Gordian’s reign the double-denarius was
nearly 48 percent pure and was well made, yet by the early 270s it
contained less than 2 percent silver and was struck haphazardly. In
this period, the decline in silver coinage mirrors the decline in
Rome’s fortunes as an empire.
In 274 the emperor Aurelian (270 to 275) reformed the empire’s
coinage, improving the intrinsic value of his precious metal coins. In
his reform the denarius was briefly reintroduced as a legitimate,
circulating coin, as were some novel base metal coins. However, the
ailing double-denarius was Aurelian’s main target: he replaced it with
a similar, but improved coin often called an aurelianianus since it is
described as such in an early sixth century A.D. text of Zosimus.
Strong opposition to Aurelian’s reforms was raised by workers
accustomed to taking their cut of the silver passing through the mint.
They led a brazen revolt at the mint in Rome, an event described
in the Historia Augusta and by the authors Eutropius and Aurelius
Victor. Thousands of lives are said to have been lost in the siege of
the mint facility. The date of the revolt is uncertain, and the loss
of life is probably exaggerated, but it likely was associated with
Aurelian’s reform of 274.
Despite resistance from mint workers, the double-denarius was
replaced with Aurelian’s new coin, which was marked with a numerical
formula in Latin (XXI) or Greek (KA). These inscriptions most likely
indicate a ratio of 20-to-1, which accords with the approximately 5
percent silver of the alloy. Some authorities see the 20-to-1 formula
as an indication of the value of this coin in relation to another,
uncertain coin, which seems a less likely explanation.
Aurelian’s new coins had large, round planchets, were well struck
with beautifully engraved dies, and had a heavy silver coating that
was flashy and far more durable than the “silver wash” of the last
issues of double-denarii.
The aurelianianus was struck by all of his successors up through
Diocletian (284 to 305), one of Rome’s most ambitious reformers, who
only stopped producing them in 294 or 295, when he completely
overhauled the Roman coinage system. ■