Ancient Roman Coin Identification: A Complete Guide for Beginners

Why Roman Coins Are the World's Most Collected Ancient Coins

Roman coins are the gateway drug of ancient numismatics. They are found in enormous quantities across Europe, North Africa, and the Middle East — still turning up in farmers' fields and metal detectorist finds 1,600 years after the fall of Rome. They are available at accessible price points. And they carry extraordinary historical weight — you can hold the portrait of Julius Caesar, Augustus, Nero, or Constantine struck during their own lifetimes.

Over 200 different emperors, empresses, and usurpers struck coins during the Roman Imperial period. Each coin is a primary historical document — sometimes the only surviving portrait of a ruler who is otherwise known only from written sources.

This guide will teach you to identify Roman coins from first principles.

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The Roman Monetary System: Denominations You Will Encounter

Understanding the denomination system is the first step in identification, because it immediately tells you the metal and period.

Gold Coins

Aureus (Republic and Early Empire, c. 46 BCE–284 CE)

Weight: ~7.3g (varies by period)

The standard gold coin of the Roman Republic and early Empire. High gold content (~95%+). Aureus means "golden" — named for its colour rather than its metal composition in the official vocabulary.

Solidus (Late Empire, 309–7th century CE)

Weight: ~4.5g

Introduced by Constantine I in 309 CE. Became the standard gold coin of the late Empire and the Byzantine Empire. More uniform in weight and purity than the earlier aureus.

Silver Coins

Denarius (Republic and Early Empire, c. 211 BCE–274 CE)

Weight: ~3–4g (declining over time)

The workhorse of the Roman monetary system for nearly 500 years. The New Testament's "penny" (Matthew 22:19) is a denarius. Initially ~95% silver; progressively debased until it was reduced to a thin silver-washed bronze coin by the 3rd century CE.

Antoninianus (218–296 CE)

Weight: ~3–5g

Introduced by the emperor Caracalla (full name Marcus Aurelius Antoninus) in 218 CE. Distinguished from the denarius by the radiate crown (a crown of sun-ray points) worn by the emperor on the obverse — versus the laurel wreath of the denarius. Initially worth 2 denarii; progressively debased like the denarius.

Siliqua (Late Empire, 4th–5th century CE)

A smaller, thinner silver coin of the late Empire.

Bronze/Copper Coins

Sestertius (27 BCE–mid-3rd century CE)

Weight: ~25–28g. Large, impressive bronze coin. The sestertius was the standard accounting unit of Roman finance.

Dupondius (c. 23 BCE–3rd century CE)

Weight: ~12–15g. Half the sestertius; distinguished by the radiate crown on the obverse.

As (c. 280 BCE–3rd century CE)

Weight: ~10–12g. A quarter of the sestertius.

Follis (Late Empire, 294 CE–c. 400 CE)

Weight: Variable (declining from ~10g to under 2g over the period).

The main bronze denomination of the late Empire after the currency reform of Diocletian in 294 CE.

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How to Identify the Emperor

The emperor's portrait on the obverse is the starting point for most Roman coin identifications. Even on worn coins, the portrait style — particularly beard or no beard, hair style, and facial features — can narrow the attribution significantly.

Reading the Obverse Legend

The legend (inscription) on the obverse names the emperor and his titles. The standard format is:

[Name] [Title abbreviations]

Common abbreviations:

• •IMP = Imperator (commander, later = emperor)
• •CAES = Caesar
• •AVG = Augustus (title of the ruling emperor)
• •PP = Pater Patriae (Father of the Fatherland)
• •PM = Pontifex Maximus (chief priest)
• •TR P or TR POT = Tribunicia Potestate (tribunician power — often with a number indicating year of reign)
• •COS = Consul (with number indicating consulship number)
• •DN = Dominus Noster (Our Lord — late Empire title)

Example: IMP CAES M AVR ANTONINVS AVG PP = Emperor Caesar Marcus Aurelius Antoninus Augustus, Father of the Fatherland = Caracalla

Portrait Features by Period

Early Empire (27 BCE–180 CE): Clean-shaven (Augustus, Tiberius, Nero). Broad, round faces. Laureate wreath (laurel crown) on most denominations.

Antonine Period (138–193 CE): Bearded emperors become the norm — Antoninus Pius, Marcus Aurelius, and Commodus all wear full beards. Hair becomes more elaborate.

Severan Period (193–235 CE): Dramatic, curly beards. Septimius Severus, Caracalla, and Geta have distinctive portrait styles.

3rd Century Crisis (235–284 CE): Soldier-emperors with short-cropped "stubble" beards, often in military dress. Coins become smaller and more debased.

Tetrarchic/Constantinian Period (284–363 CE): Stylised, non-realistic portraits. Large eyes, simplified features. Portraits become iconic rather than individualistic.

Late Empire (363–476 CE): Increasingly stylised and non-naturalistic. Diademed heads become standard.

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Reading the Reverse

The reverse of a Roman coin carries a type — a deity, personification, or scene — and a legend explaining it. The reverse type is one of the key identifiers for the specific coin issue.

Common Reverse Types

Victoria (Victory): Winged female figure, often holding a wreath and palm branch. One of the most common reverse types across all periods. Legend: VICTORIA AVG, VICTORIA AVGVSTI, etc.

Mars (god of war): Armed and helmeted figure. Common in military contexts.

Jupiter: King of the gods, often with thunderbolt. Legend: IOVI CONSERVATORI ("To Jupiter, Preserver") — very common in the 3rd–4th centuries.

Sol Invictus (Unconquered Sun): Radiate deity raising one hand. Extremely common in the 3rd century and early 4th century. SOLI INVICTO COMITI ("To the Unconquered Sun, Companion").

Providentia (Providence): Standing figure with globe and sceptre, pointing to globe.

Securitas (Security): Reclining or standing figure. SECURITAS PERPETVA, etc.

Concordia (Harmony): CONCORDIA MILITVM ("Harmony of the Soldiers") — very common.

Military reverses: VIRTVS EXERCITVS ("Valour of the Army"); soldiers with standards; the emperor receiving Victory from Jupiter.

Chi-Rho (Christian symbols): From Constantine onwards, the Chi-Rho monogram (☧, the first two Greek letters of "Christos") appears on coins and shields.

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Mint Marks on Late Roman Coins

From the Tetrarchic reform of Diocletian (294 CE) onwards, Roman coins bear mint marks in the exergue (the small area below the main reverse design, separated by a line).

Reading the mint mark:

The mint mark consists of an officina letter (the workshop within the mint) and the mint abbreviation.

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Officina letters: Γ (gamma), A, B, Δ (delta), E, S, etc. — indicating the specific workshop within the mint.

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A Step-by-Step Identification Method

Step 1: Determine the Metal

• •Gold = aureus or solidus
• •Silver (heavy, ~3–4g) = denarius or siliqua
• •Bronze/copper (large, ~25g) = sestertius or dupondius
• •Bronze/copper (medium, ~10–12g) = as or dupondius
• •Small bronze = follis or nummus

Step 2: Check the Crown Type on the Obverse

• •Laurel wreath = emperor (denarius, sestertius, as)
• •Radiate crown (sun-ray spikes) = double denomination (antoninianus, dupondius)
• •Diadem (simple headband) = late Empire (4th–5th century)

Step 3: Read Any Visible Lettering

• •Even partial lettering can identify an emperor
• •Look up the letters in standard references: Roman Coins and Their Values (Sear), OCRE (Online Coins of the Roman Empire — free online database)

Step 4: Identify the Reverse Type

• •What figure or symbol is shown?
• •What are the first letters of the reverse legend?
• •Is there a mint mark in the exergue?

Step 5: Cross-Reference Online

• •OCRE (Online Coins of the Roman Empire): numismatics.org/ocre — searchable database of over 50,000 Roman coin types
• •Wildwinds: wildwinds.com — free reference with images
• •FORVM Ancient Coins: forumancientcoins.com — identification forum and database

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What Are Roman Coins Worth?

Roman coins span an enormous range of values:

Common Bronze (sestertii, folles, nummi): $5–$50 for common types in good condition

Common Silver Denarius (common emperor in Fine condition): $30–$100

Silver Denarius (popular emperor in VF condition): $100–$500

• •Augustus: $200–$500
• •Julius Caesar: $800–$3,000
• •Nero: $150–$400

Gold Aureus (common type, Fine condition): $2,000–$10,000

Rare Emperors: Coins of rare usurpers (Quietus, Sponsian, Jotapian) can be worth $5,000–$50,000 even in worn condition

Condition is everything: A sestertius of a common emperor with a sharp, unworn portrait and green patina can be worth $500. The same type completely worn to a flat disk might be worth $5.

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Using Our Roman Coin Identifier

Upload a clear photo of both sides of your Roman coin to our free Roman Coin Identifier. For best results:

• •Photograph under raking light (light from the side) to emphasise surface relief
• •Include both obverse and reverse — the reverse type is essential for identification
• •If any lettering is visible, make sure it is clearly photographed
• •Note the metal colour: gold, silver, or bronze

The AI will identify the emperor, the reverse type, the denomination, the period, and an estimated value range. For very worn coins with limited visible detail, the AI may provide a period attribution rather than a specific emperor — for example "Roman bronze follis, Constantinian period, c. 307–361 CE."