Research led by Dr Jane Kershaw solves the mystery of early medieval money, transforming our understanding of Europe's economic and political development
In research published today in Antiquity, an international team of researchers led by Dr Jane Kershaw has solved the mystery of where the silver in 7th century Anglo-Saxon coins came from and the findings could transform our understanding of Europe’s economic and political development.
Byzantine bullion fuelled Europe’s revolutionary adoption of silver coins in the mid-7th century, only to be overtaken by silver from a mine in Charlemagne’s Francia a century later, new tests reveal.
Between 660 and 750 AD, Anglo-Saxon England witnessed a profound revival in trade involving a dramatic surge in the use of silver coins, breaking from a reliance on gold. Around 7,000 of these silver ‘pennies’ have been recorded, a huge number, about as many as we have for the rest of the entire Anglo-Saxon period (5th century – 1066).
In research published today in Antiquity, an international team of researchers led by Dr Jane Kershaw has solved the mystery of where the silver in these Anglo-Saxon coins came from by analysing the make-up of coins held by the Fitzwilliam Museum in Cambridge.
49 coins from Fitzwilliam’s collections (dating from 660 to 820 AD) were analysed for trace element and lead isotope analysis. A portable laser ablation technique ensured minimally invasive sampling of the coins whilst still achieving the high precision results of more traditional methods in which physical samples of silver are taken.
While the coins mostly contained silver, the proportion of gold, bismuth and other elements in them guided the researchers to the silver’s previously unknown origins. Different ratios of lead isotopes in the silver coins provided further clues.
The analysis revealed two major findings:
- Byzantine silver
In the 29 coins tested from the earlier period (660 – 750 AD) – which were minted in England, Frisia and Francia – the researchers found a very clear chemical and isotopic signature matching 3rd to early 7th century silver from the Byzantine Empire in the eastern Mediterranean.
The silver was homogenous across the coins and characterised by high gold values (0.6 – 2%) and a consistent isotopic range, with no distinguishable regional variations among them. No known European ore source matches the elemental and isotopic characteristics of these early silver coins. Nor is there any meaningful overlap with late Western Roman silver coins or other objects.
These coins did not recycle late Roman silver.
This provides confirmation that Byzantine silver was the dominant source behind the great seventh-century surge in minting and trade around the North Sea.
Dr Jane Kershaw, said: “These coins are among the first signs of a resurgence in the northern European economy since the end of the Roman Empire. They show deep international trade connections between what is now France, the Netherlands and England.”
The researchers emphasise that this Byzantine silver must have entered Western Europe decades before it was melted down because the late 7th century was a low point in trade and diplomatic contacts.
Co-author Rory Naismith said: “Elites in England and Francia were almost certainly sitting on this silver already. We have very famous examples of this, the silver bowls discovered at Sutton Hoo and the ornate silver objects in the Staffordshire Hoard.”
Together, Sutton Hoo’s Byzantine silver objects weigh just over 10kg. Had they been melted down they would have produced around 10,000 early pennies.
Kershaw said: “These beautiful prestige objects would only have been melted down when a king or lord urgently needed lots of cash. Something big would have been happening, a big social change.”
“This was quantitative easing, elites were liquidating resources and pouring more and more money into circulation. It would have had a big impact on people’s lives. There would have been more thinking about money and more activity with money involving a far larger portion of society than before.”
The research team hopes to establish how and why so much silver moved from the Byzantine Empire into Western Europe. Possibilities include a mixture of trade, diplomatic payments and Anglo-Saxon mercenaries serving in the Byzantine army. The new findings also raise tantalising questions about how and where silver was stored and why its owners suddenly decided to turn it into coins.
The study’s second major finding revealed a later shift away from Byzantine silver to a new source.
- The rise of Frankish silver
When the team analysed 20 coins from the second half of the period (750 – 820 AD), they discovered that the silver was very different. It now contained low levels of gold which is most characteristic of silver mined at Melle in western France. Previously obtained radiocarbon data has shown that mining at Melle was particularly intense in the 8th and 9th centuries.
The study proposes that Melle silver permeated regional silver stocks after c.750 and was mixed with older, higher-gold stocks, including Byzantine silver. In the coins minted closest to Melle, the proportion of gold was lowest (under 0.01%) while furthest away, in northern and eastern Francia, this climbed to 1.5%.
We already knew that Melle was an important mine but it wasn’t clear how quickly the site became a major player in silver production.
Naismith said: “We now know that after the Carolingian dynasty came into power in 751, Melle became a major force across Francia and increasingly in England too.”
The study argues that Charlemagne drove this very sudden and widespread surge in Melle silver as he took increasing control over how and where his kingdom’s coins were made.
England and Francia
The findings give new context to Charlemagne’s delicate diplomatic relations with King Offa of Mercia in England. Like Charlemagne, Offa took an active role in the silver trade and currency management. Both kings saw trade and politics as inseparable. In a surviving letter sent to Offa in 796, Charlemagne discussed trade in commodities as well as political exiles. The pair also entered a trade embargo when a marriage negotiation turned sour.
Naismith said: “There was a lot of communication and tension between Charlemagne and Offa. Offa wasn’t in the same league, his kingdom was much smaller, he had less power over it, and he certainly didn’t have as much silver. But he remained one of Europe’s most powerful figures who was outside of Charlemagne's control. So they maintained a pretence of equality. Our findings add to a dynamic that England and France have had for a very long time.”
Reference
J. Kershaw, R. Naismith, P. d’Imporzano and S. Merkel, ‘Byzantine plate and Frankish mines: the provenance of silver in north-west European coinage during the Long Eighth Century (c. 660–820)’, Antiquity (2024). DOI: 10.15184/aqy.2024.33
