London’s international fish trade can be traced back 800 years to the medieval period, according to new research published in the journal Antiquity.

The research, led by archaeologists from UCL, Cambridge and UCLan, provides new insight into the medieval fish trade and the globalisation of London’s food supply.

Archaeologists analysed data collected by MOLA at excavations across the capital, comprising nearly 3,000 cod bones found across 95 sites. They identified a sudden change in the origin of the fish during the early 13th century, indicating the onset of a large-scale import trade.

Cod were traditionally decapitated as part of preservation for long-range transport, meaning the researchers knew that head bones found during excavations must represent fresh fish from relatively local waters. Vertebrae, by contrast, might be either local or imported.

Comparing frequencies of the two over time, the researchers discovered the sudden switch 'from heads to tails' during the early 13th century. To confirm that the vertebrae were from distant waters, the team used biochemical signatures to match some of the individual bones to their most likely sources, with the results supporting the archaeological data perfectly: from the middle of the 13th century, the majority of sampled bones have signatures suggesting an origin in the far north, probably Arctic Norway.

The research also shows a temporary drop in imports in the late 14th century that might reflect the Black Death's impact on European trade, plus a further surge in imports from around AD1500 - coinciding with the beginnings of trans-Atlantic trade and the arrival of cod from Newfoundland on European markets.

Explore the open-access data here: https://doi.org/10.1017/S0003598X00101152 

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