When Was the Nummus Introduced?

Diocletian's government introduced the new large copper-alloy coin as part of the monetary reform conventionally dated to around AD 294. The reform also included a high-fineness silver argenteus and revised gold coinage.

The new bronze was dramatically larger than the late third-century radiates that preceded it and was produced across the Tetrarchic mint system.

How Big Was an Early Nummus?

Individual surviving coins vary because of mint standards, manufacture, circulation, corrosion, and later cleaning. The early reform coin should therefore be understood as a substantial silvered copper-alloy denomination rather than a coin with one exact surviving weight.

Was the Nummus Made of Silver?

Not in the sense of the argenteus or denarius. The reform bronze was predominantly copper alloy but contained a small amount of silver, and minting techniques concentrated silver at the surface. Fresh coins could therefore look much more silvery than their underlying metal composition suggests.

On many surviving examples that surface silvering has worn away or been lost through corrosion and cleaning.

What Appears on Diocletian's Nummus?

The best-known early reverse is GENIO POPVLI ROMANI, usually showing the Genius of the Roman People standing with a patera and cornucopia. The type was struck for members of the Tetrarchy at numerous imperial mints.

Portraits and legends identify the ruler, while mintmarks and officina marks can make these coins especially rewarding to collect by mint and workshop.

Is a Nummus the Same as a Follis?

Collectors often use the words as if they were interchangeable, but the naming is modern and historically uncertain. Follis is deeply established in older numismatic literature and remains common in auction catalogs. Nummus is frequently preferred for Diocletian's reformed bronze, but it too was a broad Latin monetary word.

The safest description is therefore something like "nummus (often called a follis)" while recognizing that the precise contemporary denomination name is debated.

Did the Nummus Stay the Same Size?

No. The large reform coin was reduced repeatedly during the early fourth century. Its changing weight and metal content are part of the complicated monetary history after Diocletian.

That does not mean every later fourth-century bronze should automatically be called a nummus. For many later issues, ancient denomination names are uncertain, which is why collectors often use neutral size categories such as AE1, AE2, AE3, and AE4.

Are GLORIA EXERCITVS and FEL TEMP REPARATIO Coins Nummi?

You will sometimes see later Constantinian and mid-fourth-century bronzes described broadly as nummi, but applying the term across the entire century can hide major changes in denomination, weight standard, and monetary system.

GLORIA EXERCITVS and FEL TEMP REPARATIO are better identified first by ruler, reverse type, mint, date, and—when the ancient denomination is uncertain—an AE size category. This avoids implying that they were simply unchanged descendants of Diocletian's original large reform coin.

Who Issued the Early Nummus?

The denomination is especially associated with the Tetrarchic rulers Diocletian, Maximian, Galerius, and Constantius I. It continued through the political upheavals that followed the First Tetrarchy, with issues for rulers including Severus II, Maximinus II, Maxentius, Licinius, and Constantine I.

For collectors, this creates a large field of rulers, mints, officinae, bust varieties, and reverse types without requiring the term to be stretched over every Late Roman bronze coin.

From the Kinzer Coins Collection

House of Constantine: Four NGC-Certified Bronzes

Constantine I closed out the nummus era. This boxed set collects NGC-certified bronzes of Constantine the Great and his three sons.

$258.00 View This Set

Are Nummi Rare?

Many Tetrarchic nummi are readily collectible, especially common GENIO POPVLI ROMANI issues, but scarcity varies enormously by ruler, mint, officina, bust, reverse, and condition. Some varieties are genuinely rare.

Large size, strong imperial portraits, surviving silvering, complete legends, and clear mintmarks can make individual examples especially attractive.

From the Kinzer Coins Collection

Ancient Rome Starter Coin: 4th-Century Bronze

An authentic Late Roman bronze from the century of the nummus, the easiest way to hold this chapter of Roman money for $19.

$19.00 View This Coin

Why the Nummus Matters

Diocletian's large reform bronze is one of the clearest physical signs of Rome's attempt to rebuild its currency after the third-century crisis. Put beside a small, heavily debased late third-century radiate, the difference is immediately visible.

It also demonstrates why Late Roman coin terminology can be difficult: the coins themselves survive in enormous numbers, but the names Romans used for particular bronze denominations are not always preserved with equal clarity.

The coin is easy to recognize. What the Romans themselves called the denomination is much harder to prove.

History wasn't just written. It was minted.

Frequently Asked Questions