Silver Isotopes and the Rise of Money

Project Information

SILVER

Grant agreement ID: 741454

DOI

10.3030/741454

Project closed

EC signature date 10 July 2017

Start date 1 October 2017

End date 31 March 2024

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 2 496 242,50

EU contribution

€ 2 496 242,50

Coordinated by

ECOLE NORMALE SUPERIEURE DE LYON
France

Periodic Reporting for period 4 - SILVER (Silver Isotopes and the Rise of Money)

Reporting period: 2022-04-01 to 2024-03-31

Summary of the context and overall objectives of the project

This project focuses on the early role of silver in Antiquity, the birth of silver coinage, and its spread around the Mediterranean from the Bronze Age until the fall of the Roman Empire. Silver by weight had been used for more than 4000 years for buying wheat, barley and pottery but it was only with the recruitment of large mercenary armies of Greek hoplites and the emergence of a strong middle class that silver coins appear in Asia Minor and Greece. In the wake of this blood money came philosophy, art, science and medicine, and a number of other wonders that we owe to the Greek world, but such a seemingly ideal situation was by nature unstable and gave way to the depredation of rich autocrats. The monetisation of the ancient Mediterranean world would only be complete at the end of the Roman Republic. Silver coinage then began to flow towards the Indian Ocean to finance the importation of incense, cotton and spices, and northwards to pay the wages of mercenaries. The disappearance of silver currency at the end of the Roman Empire heralded the end of the middle classes and of democracy. Its replacement by coins of gold and bronze would significantly widen the gap in society between rich and poor, a gap that would run through the Middle Ages and well beyond.
This work recounts the triumphal march of a metal of no real practical use, and of its most sophisticated form, silver coinage, set within their historical and economic contexts. The capture of Achaemenid treasures by Alexander the Great in 330 BCE revealed a Greek origin of most silver and illuminates the role of silver in shaping up economy and the political events around the Eastern Mediterranean. There are many threads woven into this large and intriguing canvas, of which the thickest might be: the tectonic plates that determine the unpredictable location of silver mines; numismatics that reveals the movements of precious metals; laboratory methods; classical economics and the statistical physics of wealth distribution, the environmental damage caused by agriculture since the Bronze Age, and the gradual enlargement of the known world. Distant echoes of many of these issues can be reverberate in the economic, social and environmental concerns of the modern world. This project brings together many different subjects and provides food for thought for anyone intrigued by a nagging question that has obsessed philosophers and thinkers since Plato and Aristotle.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Highlights of the SILVER Project Research Achievements

The SILVER project has made significant strides in understanding ancient silver and lead sources, along with the flow of monetary resources. Here are the key highlights:

1. Isotope Data and Techniques:
The project generated extensive new data on lead and silver isotopes from over 700 ancient silver coins and around 200 lead/silver ores across the Mediterranean, including Greece, the Balkans, and the Western Mediterranean.
Silver isotopes in coins and ores are a groundbreaking discovery. The long-term interaction of groundwater with silver artifacts required the use of drilling techniques, which most curators now oppose.
Advances in mass-spectrometry, particularly MC-ICP-MS, have revolutionized lead isotope analysis, with the group playing a pioneering role.
2. Numismatic and Geological Discoveries:
Extensive sampling in museums in Athens, Brussels, Jerusalem, and Skopje addressed new topics such as early Iron Age chopped silver, Athenian coinage, Thraco-Macedonian coinage, the coinage of Alexander the Great, and more.
Lead isotopes can indicate potential sources of silver bullion, while silver isotopes can rule out unlikely sources, combining to identify actual silver-producing mines.
3. Historical and Geological Context:
The Mediterranean, a tectonically active zone, has abundant silver due to volcanic and subvolcanic activity from recent orogens (<80 million years). Silver is a present of plate tectonics to the Mediterranean.
Early sources of silver bullion, as early as 2600 BCE, were mainly around the Aegean Sea, with significant production in regions like the Taurus in Asia Minor, Sardinia, and Iberia.
4. Major Findings:
The project confirmed that the origins of the Achaemenid treasures, captured by Alexander the Great, were predominantly Aegean.
Silver coinage from the Aegean was crucial for trade development post-6th century BCE. The return of Greek mercenaries played a key role in the rise of democracy and the flourishing of Greek culture.
5. Isotopic Analysis and Recycling:
Lead and silver isotopes in coinage reveal whether silver was sourced from ores or recycled bullion. This principle, new to numismatics, shows that recycling played a role in the Roman economy, especially during the Second Punic War.
Principal Component Analysis of lead isotopes in silver coinage suggests Greek cities primarily used a single dominant bullion source with minimal external silver integration.
6. Regional Contributions and Techniques:
Gaul and possibly modern Tunisia were sources of silver before the Roman conquest.
The project introduced the analysis of platinum-group elements and gold in silver coinage, confirming that large-scale salt cementation was unlikely used by Athenians.
7. Innovative Databases and Algorithms:
SILVER developed two new databases: one for die studies to assess mint production and one for overstrikes to evaluate mechanical recycling without melting (https://silver.knowledge.wiki/SILVER).
A new three-dimensional search algorithm, validated by a chi-squared test, is a unique contribution.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The project set up the stage for an integrated history of silver around the Mediterranean from the Bronze Age in Egypt to the end of the Roman Empire. It illustrates the combined roles of mercenaries and trade in triggering the rise of minted silver which coincided with the explosion of trade, the beginning of democracy, and the advent of classical Greek culture. It shows how silver hoarding in Achaemenid palaces was incapable of thwarting the unstoppable power of coinage.

Athenian silver Tetradrachm "Wappenmünzen" struck in 515 BCE at the time of tyrant Hippias