What Is a Follis? The Bronze Coin of Diocletian's Reforms
What Is a Follis? The Bronze Coin of Diocletian's Reforms
By AD 294, Rome's Money Was in Crisis. Diocletian's Answer Was a Large New Bronze Coin, and for Many Collectors, It's the First Tangible Link to the Late Roman Empire.
By the end of the third century AD, Rome's monetary system was in crisis.
Decades of civil wars, inflation, and repeated currency debasement had left many of the Empire's traditional denominations struggling to inspire confidence. The silver denarius had largely disappeared, the antoninianus had lost much of its silver content, and the once-familiar bronze denominations of earlier centuries were fading from circulation.
In response, Emperor Diocletian introduced sweeping monetary reforms around AD 294. One of the most important features of those reforms was a new large bronze denomination that modern collectors know as the follis. Although historians continue to debate whether Romans themselves called this denomination a "follis," the name has become the standard term among collectors today. For many people beginning the hobby, the follis is their first tangible connection to the Late Roman Empire.
What Was a Follis?
The follis was a large bronze denomination introduced during the monetary reforms of Diocletian. Modern collectors almost universally call this denomination a follis, although many modern scholars prefer the term nummus because ancient sources do not clearly identify the coin by the name follis. Some evidence suggests that follis originally referred to a money bag or purse rather than a specific coin.
Regardless of its ancient name, this denomination represented a fresh beginning for Rome's monetary system. Unlike the heavily debased antoninianus that preceded it, the new bronze coin was carefully manufactured and originally covered with a thin silver wash, giving it a brighter and more valuable appearance.
Why Was the Follis Created?
Diocletian inherited an empire facing severe economic challenges. Years of inflation had undermined confidence in Roman currency, making trade increasingly difficult. His monetary reforms sought to restore stability by introducing a new system of gold, silver, and bronze denominations with more consistent standards.
These reforms accompanied the broader political reorganization known as the Tetrarchy, in which the Roman Empire was governed by two senior emperors (Augusti) and two junior emperors (Caesares). The new bronze denomination became one of the principal coins of this reformed monetary system. Although inflation would continue to challenge the Empire, Diocletian's reforms marked one of the most ambitious attempts to stabilize Roman money in its history.
What Did a Follis Look Like?
Early folles were much larger than the small Late Roman bronze coins familiar to many collectors today.
- A laureate portrait of the emperor on the obverse
- Detailed reverse designs promoting imperial stability, military strength, or the traditional Roman gods
- A bronze core covered with a thin silver wash
One of the most famous reverse types is GENIO POPVLI ROMANI, meaning "To the Genius of the Roman People," celebrating the prosperity and unity of the Empire under Diocletian's reforms. Over time, the denomination gradually became smaller as later emperors reduced its size and weight.
Why Are Constantine's Bronze Coins Smaller?
One question nearly every beginning collector asks is why Constantine's coins are so much smaller than Diocletian's. The answer lies in decades of gradual monetary adjustment.
Although Constantine continued striking bronze coins descended from Diocletian's reformed bronze coinage, they became progressively smaller and lighter throughout the fourth century. Today, collectors often classify these coins using modern size designations such as AE1, AE2, AE3, and AE4. These are modern numismatic classifications, introduced in the twentieth century and based on a coin's diameter. They are not ancient Roman denominations.
Why Are Most Folles Green?
One of the first things collectors notice is that most surviving folles no longer appear silver. Originally, these coins were coated with a thin silver wash, but centuries of circulation and burial usually wore that delicate surface away.
Today, most examples display green, brown, or dark olive patinas formed naturally as the bronze reacted with moisture, oxygen, and minerals in the soil. Collectors generally value original patinas because they help preserve the coin while giving each example its own distinctive appearance.
Why Collectors Love Folles
The follis is one of the best introductions to Roman coin collecting.
- Affordable prices
- Large, attractive designs
- Connections to Diocletian and Constantine
- Beautiful mint marks and reverse types
- Excellent opportunities to study Late Roman history
Because of their affordability and historical significance, folles remain one of the most popular entry points into Roman coin collecting.
Famous Folles Every Collector Should Know
Among the most popular folles are those that span the transition from the pagan Roman Empire to the increasingly Christian Late Roman Empire.
- Diocletian. Creator of the monetary reforms
- Maximian. Early Tetrarchic issues
- Galerius. Large bronze folles from the Tetrarchy
- Constantius I. Father of Constantine the Great
- Constantine the Great. Early folles and later reduced bronze coinage
- Licinius I. Important rival of Constantine during the early fourth century
Why Did the Follis Change?
The large bronze denomination introduced by Diocletian did not remain unchanged. Throughout the fourth century, its size, weight, and silver coating were gradually reduced as economic conditions evolved.
By the reign of Constantine and his successors, the once-large coin had become noticeably smaller, eventually giving rise to the diverse Late Roman bronze series familiar to collectors today. Its evolution reflects the changing needs of an empire adapting to new political and economic realities.
Holding History
Holding a Roman follis is like holding the beginning of a new chapter in Roman history. It represents the moment when the Empire attempted to recover from one of its greatest crises through sweeping reforms that reshaped its government, military, and economy.
For many collectors, a follis is more than an affordable ancient coin. It is the starting point for understanding the transformation of the Roman Empire into the Late Roman and Byzantine worlds.
A follis is the starting point for understanding the transformation of Rome into the Late Roman and Byzantine worlds.
History wasn't just written. It was minted.
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Authentic ancient coins, NGC-certified, guaranteed authentic, with 30-day returns. Large folles of Diocletian and Constantine, one of the best entry points into the hobby.
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