In November A.D. 284, a dispirited Roman army was marching westward
after a campaign against the Persians.
En route, the emperor Numerian was found dead in his litter; the
army executed his murderer and chose one of their commanders, Diocles
— better known as Diocletian — as their new emperor.
Diocletian was one of Rome’s most important emperors, and his
reign marked a transformation in Roman society. His first innovation
was to appoint a colleague, Maximian, as co-ruler. This was a
practical measure since the empire was too vast and troubled to rule
alone, and Diocletian had no son with whom he could share the throne.
Initially, Maximian held the subordinate rank of caesar but was
soon hailed augustus, and he was equal to Diocletian in all respects
except that he could not legislate. The two emperors worked together
tirelessly to defend the empire, with Diocletian based in the East and
Maximian in the West.
In A.D. 293 Diocletian expanded his system to include two caesars:
Galerius as his assistant and Constantius I to help Maximian. For the
first time in history the Roman Empire was ruled by four men, an
innovation that gave rise to “Tetrarchy” as a moniker for the period.
Four rulers made it possible to respond to crises in all parts of
the empire, but it also meant a greatly enlarged bureaucracy, which
was top-heavy and expensive. By now life had become draconian,
oppressive and a mere exercise in survival. This grim reality caused
people to focus increasingly on the afterlife and gave momentum to the
rise of Christianity.
During the Tetrarchy (circa A.D. 284 to 313) coins were struck in
the names of 15 people. The billon coins of most issuers are readily
available, which means there is plenty to collect and a meaningful
collection can be built on a modest budget. Though the coins are
neatly struck, their simplistic artistry is not to everyone’s taste;
they might even be considered an acquired taste.
The earliest coinage system of Diocletian was no different than
that of his immediate predecessors. However, in 293 or 294 Diocletian
reformed the coinage as part of his larger effort to regulate wages
and the prices of goods and services.
The empire’s most valuable standard issue coin — the gold aureus —
continued to be struck, though it was stabilized at the weight of 60
to the Roman pound. However, the rest of the system was gutted, and
existing denominations were replaced with new ones.
The most important new denomination was the nummus (follis), a
large billon coin that contained about 5 percent silver. Since much of
that silver was concentrated on the surface, the nummus appeared more
valuable than it was. Sometimes the mirror-like, silvery surfaces
remain intact — even after their discovery and conservation more than
1,700 years later. Another of Diocletian’s new coins was a dime-sized
silver piece, today called an argenteus, which was struck at 96 to the
pound. The coin was a failure from the outset because it was too good
for the times. It was of such high purity that it was exported or
hoarded while the overvalued nummus lingered in circulation.
Several base metal coins were also introduced: a “radiate” and a
“laureate.” The radiate is so-called because the issuer is portrayed
wearing a radiate crown, and the laureate because he wears a
laurel-leaf crown. The former is relatively scarce, and the latter is
rare, which suggests they played only a minor role in the system.
Diocletian’s reforms were generally unsuccessful, especially those
associated with economics. His attempt to regulate the economy failed
miserably, and in fact made matters worse. After his attempt to set
maximum prices on goods and services, inflation skyrocketed and
economic activity was forced underground, where it bypassed taxation.
His attempt to restrict personal freedoms and to increase revenues
also tended to create the opposite effect. For example, he tried to
force the increasingly powerful Christian population to make
sacrifices to the pagan gods, but to no avail. By the end of his
reign, Diocletian recognized that his heavy-handed tactics had failed.
With these depressing reversals, a serious health crisis and
(apparently) the ambitions of one of his presumed successors, the
Caesar Galerius, Diocletian chose to abdicate in A.D. 305. This had
never happened before in the Roman Empire, as the reigns of all
previous emperors had ended only with their deaths, natural or violent.
With the joint retirement of Diocletian and Maximian, the two
caesars (Galerius and Constantius I) moved up to become emperors in
their place. Even though Galerius was technically the subordinate
partner, he assumed the dominant role. One of his first acts was to
appoint two new caesars — a loyal comrade, Severus II, and a nephew,
Daia (Maximinus II Daia).
This decision was disastrous since two important candidates were
passed over — Maximian’s son, Maxentius, and Constantius I’s eldest
son Constantine I (later known as “the Great”). Added to this mix was
Maximian’s desire to return to power, for he had unwillingly abdicated
under pressure from Diocletian.
Galerius’ misstep sparked rebellions in Italy and the Western
provinces in A.D. 306, which gave rise to a series of civil wars that
persisted until A.D. 324, when Constantine I defeated his last
opponent, Licinius. During this period the political landscape was
complex and unstable. While this was unfortunate for the Romans, it is
a bonanza for numismatists since coins illustrate many of the
political, military, social and religious developments of the age.
The coinage of those 18 years is complex and interesting, and
finding the more obscure items can be a real challenge. The good news,
however, is that most of the coins are affordable and not too
difficult to find, making this one of the best areas of ancient
coinage to collect.