Long-Distance Trade Revealed at Medieval Danish Viking Center

Revolutionary new advances in radiocarbon dating techniques have enabled scientists to more precisely determine the chronology and dynamics of Viking Age trade networks based on a medieval Danish Viking center near Ribe, Denmark. To be published today in the journal Nature, the Danish Viking center study uses a technique that pinpoints radiocarbon data to a single year.

In the twentieth century, radiocarbon dating resulted in sweeping changes in archaeological techniques that considerably expanded our knowledge of the past. Further advances occurred when radiocarbon data was calibrated to calendar years and could be applied to increasingly small samples. 

Using single tree rings and rapid changes in levels of atmospheric carbon during solar particle events (SPE) or years of extreme solar flares, leading-edge carbon dating studies produce better annual radiocarbon datasets called IntCal20. With these new datasets, radiocarbon dating can be applied to urban sites, which require higher-resolution data, unlike earlier datasets. As a result, carbon 14 spikes can be seen in radiocarbon date sequences across years including an SPE year. With these advances, radiocarbon dating becomes very precise even in SPE years and can even identify the exact year of an infrequent event.

The stratigraphy of the Danish Viking center excavation site, exposed in a profile from which box samples are being taken. (The Museum of Southwest Jutland / Nature)

Viking Center Trade Networks Analyzed In New Ways

The new study uses single-year radiocarbon dating to arrive at a Bayesian model to determine the chronological stratification of an important early medieval Viking center in Ribe in Denmark in relation to trade networks. Four groups of trading artifacts have been recovered at the Ribe site: west European glass beads and ceramics; Norwegian artifacts that include reindeer antlers and whetstones; metal ornaments, particularly Berdal-style Viking brooches, locally produced for overseas export; and Middle Eastern glass beads.

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Using dendrochronological analysis and the new radiocarbon datasets, the researchers determined the chronology of the four categories of artifacts identified at the site. In doing this, they were helped by exactly pinpointing an SPE to AD 775 in the archaeological layer, just before the Viking Age got started in 793 AD according to most scholars. The beginning of the Viking Age is dated from the appearance of artifacts characteristic to the age in Scandinavia and the beginning of Viking attack raids on Britain and Ireland.

This advanced radiocarbon dating precision helped the authors of the study to date the trade artifacts recovered from the Ribe Viking center and provide chronological anchor points for the period from 760 to 800 AD.

Imported beads from the Middle East found at the Ribe Viking center in Denmark, which probably got there via trade routes from the Baltic Sea through Russia. (The Museum of Southwest Jutland / Nature)

In Ribe’s early phases, trade connectivity, as arrived at by the dating of the artifacts, is exclusively with western Europe. Two groups of artifacts, glass beads made of recycled material from broken drinking vessels or Roman mosaic tiles and ceramics typical to the Rhine area, belong to this phase of the Ribe Viking center’s trade connections.

Whetstones made of Norwegian schist arrive in the next phase, around AD 740, implying that maritime trade within Scandinavia grew before the North Sea Viking raids began around AD 790. 

Next, wasp-type beads, produced between AD 750 and 790, provided evidence of trade with the Baltic Sea region.

Finally, the study was able to date the introduction of glass beads from the Middle East to AD 785-810. This is also the period during which the Berdal-style brooches were produced. Berdal style is a Norse art and craft style from the beginning of the Viking Age.

Vikings ships on the move in the Viking Age, which gave birth to new trade networks that reached exotic places in the Mediterranean and in North America. (Vlastimil Šesták / Adobe Stock)

Implications for Viking Age Trade Network Timelines

Crucially, this new study weighs in on the long-ranging debate on the timings and dynamics of long-distance trading interactions in the Viking Age. It has been argued by some that a global trade network, based on the growing Islamic empire in the Middle East, was the economic catalyst for Viking Age trade as well as for western Europe’s prosperity under Charlemagne. However, others have questioned this hypothesis and believe that trading developments in Viking Scandinavia were mostly local.

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By providing a precise chronology, the authors of the latest study were able to establish that the growth of Viking Age trade, urbanism, and piracy was a prolonged and complex process with multiple triggers. A single explanation of the Viking phenomenon will thus not suffice. They suggest that the beginning of the Viking Age may have been associated with competition for trade routes.

Moreover, the authors believe that by using their new radiocarbon dating model links between rapid societal changes in the past, including economic and climatic change trends, will be easier to understand.

Top image: Beads found in at the medieval Ribe, Denmark Viking center, which was the basis for a new radiocarbon dating model applied to Viking Age trade. Source: The Museum of Southwest Jutland / Nature

By Sahir Pandey