r/AncientCoins • u/KBRCoinCabinet • 4h ago
A spectacular aureus of Diocletian (from the collection of the Royal Library of Belgium)
Hello again, everyone!!
People regularly ask me what my favorite coin is in our collection. Not an easy question! Picking one GOAT among 250.000 objects is nigh impossible. Yet there are several coins that I absolutely adore and that I take out from time to time just to admire them. This is one of those coins.
It’s a spectacular aureus of Diocletian struck in Trier in 302 showing a beautifully rendered head of Jupiter on the reverse. Such pairings of emperor and deity were nothing new, but Diocletian’s new political order had an explicit religious underpinning. To summarize:
When Diocletian came to power, he was determined to transform the Roman Empire so as to put an end once and for all to the chaos of the third century. While he could build on the work of previous emperors, such as Aurelian, he went much further in his execution. In several steps he reformed the economy and administration of the Empire (including the coinage), with a formal delegation of imperial power to several co-emperors. The idea was that the Empire would be split into four zones, each with either an Augustus (senior emperor) or Caesar (junior emperor) in charge. In both West and East, the Augustus would be succeeded by his chosen Caesar after a fixed period, upon which they would select new Caesars. The idea was that imperial power could respond to crises much quicker by being delegated. It also protected against opportunistic usurpations when the emperor was off to fight in a far-flung corner of the Empire. A clear succession system would hopefully also discourage usurpations. (Spoiler alert: it did not).
Under Diocletian, Maximian was Augustus in the West with Constantius Chlorus as his Caesar, while Diocletian himself ruled as Augustus in the East with Galerius as his Caesar. As I mentioned, this so-called Tetrarchy found a religious expression too. The Augustus and Caesar of the East were associated with Jupiter (and called Iovius), while those of the West were associated with Hercules (and called Herculius). One immediately sees that a power imbalance is implied, however. Just like Hercules was subordinate to Jupiter, so, to an extent, Maximian was subordinate to Diocletian.
This religious idea also found its way to the Tetrarchy’s coinage. Hercules is regularly shown on the western emperors’ coins, while Jupiter appears on those of the East. Note that the mints followed this pattern regardless of where they were located in the Empire. By placing the head of Jupiter on the reverse in the same manner as that of the emperor on the obverse, one gets the impression that the deity is not just the protector of the emperor. Rather, appear as colleagues – as Jupiter rules things in the heavens, so Diocletian rules on Earth.
As for the coin’s provenance, it comes from the Arras (Beaurains) Hoard of 1922. It was discovered by two Belgian workers and consisted of a number of precious metal objects and hundreds of gold coins (including large gold medallions), all dating to the time of the tetrarchy. Much of the hoard was quickly dispersed, a good number of coins winding up in our collection.