Roman Coinage: The Complete Guide

From Republic to Empire – Explore 800 years of numismatic history, propaganda, and economic evolution

300 BC – 476 AD (West) Roman Empire Beginner → Expert
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SECTION 1 — WHAT ARE ROMAN COINS?

Definition and historical scope of Roman coinage

Definition of Roman Coinage

Roman coins are the official currency issued by the Roman Republic and Empire from approximately 300 BC to AD 476 in the West, continuing in the Byzantine Empire until AD 1453. These coins served as economic instruments, political propaganda, and historical records of the Roman state.

Roman Coinage Timeline

Roman Republic
c. 300–27 BC
Gods, symbols, moneyer issues
Roman Imperial
27 BC–476 AD
Emperor portraits, propaganda
Byzantine Transition
330–1453 AD
Christian symbolism, solidus

Key Differences: Republican vs Imperial

Republican Coinage
  • Portraits: Gods, not living individuals
  • Authority: Issued by moneyers (tresviri)
  • Designs: Family symbols, mythology
  • Purpose: Economic, some propaganda
Imperial Coinage
  • Portraits: Emperor and family
  • Authority: Emperor's name
  • Designs: Propaganda, achievements
  • Purpose: Political, economic control

Market Dominance

Roman coins dominate the collector market due to abundance, historical importance, and wide range of affordable options from common bronzes to rare gold.

Propaganda Tools

Coins were mass media – announcing military victories, imperial succession, building projects, and virtues to citizens across the empire.

Historical Records

Coins provide primary evidence for emperor portraits, titles, events, and economic conditions not always recorded in literary sources.

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SECTION 2 — ORIGINS OF ROMAN COINAGE

From bronze bars to Greek-inspired coinage

Pre-Coinage Barter System

Before coinage, Romans used bronze bars (Aes Rude - rough bronze) measured by weight for transactions. This evolved into Aes Signatum (stamped bars) around 280 BC.

1
Aes Rude (c. 600–280 BC)

Irregular bronze lumps traded by weight. No standard shape or marking.

2
Aes Signatum (c. 280–241 BC)

Cast bronze bars with simple designs (elephant, anchor). Stamped but not standardized.

3
Aes Grave (c. 241–212 BC)

Cast bronze coins with standard weights. First true Roman coinage system.

Why Rome Adopted Coinage Late

Compared to Greek neighbors, Rome adopted coinage relatively late (early 3rd century BC) due to:

  • Agricultural economy: Less need for sophisticated currency
  • Traditional values: Suspicion of foreign innovations
  • Military expansion: Contact with Greek cities necessitated coinage
  • War funding: First Punic War (264–241 BC) required efficient payment system

Greek Influence

Roman coinage was heavily influenced by Greek models:

  • Technology: Adopted Greek striking methods
  • Denominations: Based on Greek drachm/obol system
  • Artistic style: Early coins show Greek artistic influence
  • Silver standard: Denarius based on Greek didrachm

Technical Specifications

Cast vs Struck Coins

Cast: Early bronze coins poured into molds (Aes Grave)
Struck: Later coins hammered between dies (all silver/gold)

Early Weight Systems

Libral standard: As = 1 Roman pound (327g)
Semi-libral: As = 1/2 pound (164g)
Uncial: As = 1/12 pound (27g)

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SECTION 3 — METALS IN ROMAN COINAGE

Gold, silver, and bronze through Roman history

Three-Metal System

Roman coinage operated on a three-metal system: gold for high-value transactions, silver for everyday commerce, and bronze/copper for small change.

Gold

High Value
Aureus (27 BC–309 AD)

Weight: ~7.3g (Augustan standard)
Value: 25 denarii
Purpose: Imperial payments, large transactions

Solidus (309 AD onward)

Weight: ~4.5g (Constantinian)
Value: Stable gold standard
Purpose: Byzantine gold standard for 700 years

Silver

Commercial Standard
Denarius (211 BC–244 AD)

Weight: ~4.5g (Republican) to ~3g (late)
Purity: 95% to <50% over time
Decline: Severely debased by 3rd century

Antoninianus (215–294 AD)

Weight: ~5g (initially)
Value: 2 denarii (nominally)
Feature: Radiate crown on emperor portrait

Bronze/Copper

Everyday Currency
Republican System

As: Basic unit
Dupondius: 2 asses (brass)
Sestertius: 4 asses (orichalcum)

Imperial System

Follis: Diocletian's reform (294 AD)
Nummus: Constantine's coin
AE: Generic bronze coins

The Great Debasement

Republican (211–27 BC)

Denarius: ~95% silver

Early Imperial (27 BC–68 AD)

Denarius: ~90% silver

Nero's Reform (64 AD)

Denarius: ~80% silver

Severan (193–235 AD)

Denarius: ~50% silver

Crisis of 3rd Century

Antoninianus: <5% silver

Economic Impact

Hyperinflation

Debasement led to price spirals. Diocletian's Edict on Maximum Prices (301 AD) failed to control inflation.

Loss of Confidence

Citizens hoarded older, purer coins (Gresham's Law). Barter returned in some areas.

Taxation Problems

State demanded taxes in gold while paying soldiers in debased silver.

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SECTION 4 — ROMAN DENOMINATIONS (CRITICAL)

Understanding the complex Roman monetary system

Roman Monetary System Evolution

The Roman monetary system evolved significantly over centuries, with major reforms by Augustus, Nero, Diocletian, and Constantine.

Coin Metal Value (in As) Weight Visual Identifier Period
Aureus Gold 400 asses ~7.3g Gold color, emperor portrait 27 BC–309 AD
Denarius Silver 16 asses ~3.9g Silver, laureate head 211 BC–244 AD
Antoninianus Billon* 2 denarii ~4.5g Radiate crown 215–294 AD
Sestertius Orichalcum 4 asses ~25g Large size, golden color 23 BC–260 AD
Dupondius Orichalcum 2 asses ~13g Radiate crown (emperors) 23 BC–260 AD
As Copper 1 as ~11g Laureate head 280 BC–260 AD
Follis Bronze Varies ~10g Large bronze, silver wash 294–310 AD

*Billon = debased silver with high copper content

Visual Identification Keys

Radiate Crown

Double value marker:
• Antoninianus = 2 denarii
• Dupondius = 2 asses

Size Matters

Roman coins sized by value:
• Sestertius: ~30mm (largest common)
• Denarius: ~18mm
• As: ~25mm

Metal Color

Distinguish by appearance:
• Orichalcum: Golden brass
• Copper: Reddish-brown
• Billon: Silvery-gray

Military vs Civilian Usage

Military Payments
  • Gold aurei: Officer bonuses, retirement
  • Silver denarii: Regular soldier pay
  • Antoninianus: 3rd century army pay
  • Special issues: Donatives to legions
Civilian Commerce
  • Sestertii: Major purchases, taxes
  • Asses: Daily wages, market goods
  • Quadrans: Smallest coin, bath entry
  • Local coinage: Provincial issues
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SECTION 7 — ROMAN REPUBLICAN COINAGE

The complex world of Republican moneyers and family propaganda

The Moneyer System

Republican coins were issued by tresviri monetales (three moneyers), young aristocrats beginning their political careers. Each moneyer could put personal/family symbols on coins.

Family Propaganda

Moneyers used coins to promote their family's history and achievements:

  • Ancestor portraits (rare before Caesar)
  • Family names in legends
  • References to family accomplishments
  • Mythological ancestors (Venus, Mars, etc.)

Complex Symbolism

Republican coins feature intricate symbols requiring decoding:

  • Control marks for mint batches
  • Symbols referencing moneyer's name
  • Puns and visual wordplay
  • Historical event commemorations

Famous Republican Types

EID MAR Denarius
42 BC Extremely Rare

Brutus' coin commemorating Caesar's assassination. Most famous Roman coin.

Elephant Denarius
49 BC Rare

Caesar's coin celebrating victory over Pompey. Features elephant trampling serpent.

Sextus Pompey Fleet
42-40 BC Scarce

Features the lighthouse of Messana and sea monster, celebrating naval power.

L. Aemilius Buca
44 BC Common

Features Apollo and lyre, issued just after Caesar's assassination.

Dating & Identification Challenges

No Imperial Dates

Republican coins lack regnal years or consular dates. Dating relies on moneyer identification and style analysis.

Moneyer Identification

Hundreds of moneyers with similar names. Requires knowledge of Roman aristocratic families.

Symbol Decoding

Personal symbols require understanding of Roman iconography and wordplay.

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SECTION 10 — HOW TO IDENTIFY ROMAN COINS

Master method for identifying any Roman coin

1

Examine the Portrait

Identify emperor or figure. Note hairstyle, facial features, crown type (laureate/radiate), and any distinctive characteristics.

Pro Tip: Use portrait reference guides. Hairstyles are particularly diagnostic.
2

Read the Legend

Decipher the inscription around the portrait. Look for imperial names, titles (IMP, AVG, CAES), and mint marks.

Pro Tip: Learn common abbreviations. Legends often give emperor name and titles.
3

Analyze Reverse Type

Identify the reverse design: gods, personifications, buildings, or events. Note any inscriptions in exergue.

Pro Tip: Reverse types often commemorate specific events or virtues.
4

Check for Mint Marks

Look for mint letters/ symbols below reverse design or in field. Common mints: R (Rome), ANT (Antioch), TR (Trier).

Pro Tip: Mint marks often include officina letters (A, B, Γ, Δ) for workshop.
5

Determine Metal & Size

Identify metal (gold, silver, bronze) and measure diameter. Compare to known denominations.

Pro Tip: Use calipers for accurate measurement. Weight can confirm denomination.
6

Assess Style & Period

Evaluate artistic style: crude (3rd century), realistic (Trajan/Hadrian), stylized (Late Roman).

Pro Tip: Style often indicates period even when legends are worn.

Essential Identification Tools

Reference Books

RIC (Roman Imperial Coinage), RSC (Roman Silver Coins), Sear (Greek Imperial Coins)

Magnification

10x loupe for legend reading and detail examination

Measuring Tools

Digital calipers for precise diameter measurement

Digital Scale

0.01g accuracy for weight verification

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SECTION 13 — COLLECTING ROMAN COINS

Practical guide for building a Roman coin collection

Beginner-Friendly Coins

Late Roman Bronzes

4th century AE coins are abundant, affordable ($10-$50), and often have clear legends.

Easy
Provincial Bronzes

Coins from Roman provinces offer variety and history at reasonable prices.

Easy
Common Denarii

Later emperors like Gordian III or Philip I have affordable silver coins.

Medium

Budget Collection Strategies

Type Collection

One example of each denomination: As, Dupondius, Sestertius, Denarius, Antoninianus

$$
Emperor Collection

Focus on one dynasty (e.g., Severans) or collect "Twelve Caesars"

$$$
Theme Collection

Collect by reverse type: animals, gods, buildings, military themes

$

Storage & Care Guidelines

Never Do
  • Never clean with abrasives or chemicals
  • Never store in PVC flips or envelopes
  • Never handle without clean hands
  • Never polish or attempt to "shine" coins
Always Do
  • Use archival storage (Mylar flips, acid-free trays)
  • Store in stable temperature/humidity
  • Handle by edges or with cotton gloves
  • Document each coin with photos and details

Cleaning Myths Debunked

"Vinegar Cleans Coins"

Truth: Vinegar (acid) destroys patina and causes irreversible damage.

"Brass Polish Shines Bronze"

Truth: Removes original surface and reduces value by 90%.

"Soaking in Olive Oil Helps"

Truth: Can cause dark staining and doesn't improve coin preservation.

Expert Advice: Only professional conservators should clean ancient coins. For collectors, "less is more."