A recent study by researchers from the Universities of Cambridge and Nottingham challenges the long-held belief that Britain’s industrial economy collapsed after the Romans left. The findings, published in the journal Antiquity, indicate that metal production continued beyond the Roman period and experienced significant growth during the Viking age.
The research focused on a five-metre sediment core taken from Aldborough in Yorkshire, a site known for its historical role in metal production. The analysis revealed that while there were low levels of lead and iron production during the 4th to early 5th centuries AD, there was a notable increase in iron smelting—and to a lesser extent, lead—through the 5th to mid-6th centuries. This activity used similar ore sources and coal as those employed during Roman times.
Professor Martin Millett of Cambridge’s Faculty of Classics and Fitzwilliam College commented: “This collaborative work which forms part of a long-term project at Aldborough adds a new dimension to our understanding of the history of this important Roman town in the immediately post-Roman period. It has significant implications for our wider understanding of the end of Roman Britain.”
The study also found that metal production did not decline until around 550-600 AD, coinciding with evidence from Mediterranean and French texts describing waves of bubonic plague and possibly smallpox during this time. DNA evidence from Edix Hill cemetery in Cambridgeshire supports these accounts, indicating deaths from bubonic plague in eastern England from the 540s.
Lead author Professor Christopher Loveluck from Nottingham’s Department of Classics and Archaeology said: “The Aldborough sediment core has provided the first unbroken continuous record and timeline of metal pollution and metal economic history in Britain, from the 5th century to the present day.”
Unlike previous studies that relied on records far removed from their sources, such as upland peat cores or mountain glaciers, this research analyzed data directly from an area central to historic metal production. The team combined sediment analysis with excavation results and landscape studies at Aldborough over two millennia. Charles French, Emeritus Professor of Geoarchaeology at Cambridge, contributed expertise in interpreting buried landscapes through archaeological techniques.
Results showed another surge in lead and iron production before Viking arrival, with further expansion under Viking control between the late 8th and 10th centuries. This suggests regional economic growth not previously documented beyond individual sites.
A decline occurred through the 11th century, followed by renewed large-scale production from the mid-12th to early 13th centuries. These findings align with written records documenting increased lead output in Yorkshire and broader Britain between 1160s–1220s; similar pollution spikes have been detected in Swedish lakes and Alpine ice cores.
Production fell again during the 14th century but recovered until it was interrupted by Henry VIII’s Dissolution of the Monasteries (1536-38). “It became uneconomical to make fresh metal because it was ripped off all the monasteries, abbeys and religious houses,” Professor Loveluck explained. “Large-scale production resumed in the later 16th century to resource Elizabeth I’s Spanish and French wars.”
The Aldborough Roman Town Project—directed by Dr Rose Ferraby and Professor Martin Millett—has conducted extensive geophysical surveys using magnetometry over nearly 120 hectares within Aldborough and its surroundings. Ground Penetrating Radar has also been deployed selectively within town limits for detailed structural analysis. Excavations since 2016 have re-examined earlier trenches to provide further context.
Funding for this research came from The British Academy and University of Cambridge.
“It became uneconomical to make fresh metal because it was ripped off all the monasteries, abbeys and religious houses,” Professor Loveluck explains. “Large-scale production resumed in the later 16th century to resource Elizabeth I’s Spanish and French wars.”
“This collaborative work which forms part of a long-term project at Aldborough adds a new dimension to our understanding of the history of this important Roman town in the immediately post-Roman period. It has significant implications for our wider understanding of the end of Roman Britain.” – Professor Martin Millett
“The Aldborough sediment core has provided the first unbroken continuous record and timeline of metal pollution and metal economic history in Britain, from the 5th century to the present day.” – Professor Christopher Loveluck