Did the Vikings Create Trade Networks, or Just Steal Them?
How Irish Monasteries and Their Trade Networks May Have Shaped the Viking Path to France.

The discovery of three silver deniers from the reign of Charles the Bald in regions around the Irish Sea—Puddington in Cheshire, Llanbedrgoch in Anglesey, and the famed Cuerdale Hoard in Lancashire—may provide crucial evidence of a trade connection between the Irish Sea and the Bay of Biscay by the 840s, well within the Viking Age. Minted in Melle, France, these coins are tangible markers of a trade network that may have extended across disparate regions. Notably, the presence of one of these coins in the Cuerdale Hoard—a massive collection of Viking silver—strongly implies that this trade network would have at least been in part under Viking control by this period. This prompts an essential question: Did the Vikings establish this trade or co-opt an existing system that preceded their involvement?
We must examine the evidence for preexisting trade routes and cultural links to answer this. Irish-tradition monasteries, which spread from Ireland to northern France in the 6th and 7th centuries, played a pivotal role in early medieval contacts and commerce. These monastic centers, connected by a shared religious heritage and economic activity, may have served as hubs for exchanging goods such as manuscripts, wine, salt, and silver. Such a network would have predated Viking involvement, particularly in the Bay of Biscay region. These monasteries may not have been simple centers of faith but integral nodes in a more extensive trade system.
This context offers a plausible explanation for one of the Viking Age’s earliest mysteries: why the Vikings, after their initial raid on Lindisfarne in 793 and Iona in 795, leaped from the Irish Sea to the Bay of Biscay as early as 799. Noirmoutier, an island off the western coast of France, was the site of one of the first recorded Viking raids outside the British Isles. Why bypass closer and potentially richer targets, such as Frisia or Normandy? The answer may lie in the existing trade connections between Irish-tradition monasteries in Ireland and those in the Bay of Biscay. The shared monastic culture and their well-established trade network would have provided the Vikings with a clear roadmap, leading them directly to Noirmoutier, a significant hub for salt production and trade.
By targeting Irish-tradition monasteries, the Vikings may have exploited a preexisting network that was both economically valuable and geographically expansive. The raid on Noirmoutier in 799, just six years after Lindisfarne, may demonstrate that the Vikings were not merely raiding at random but strategically following well-trodden trade and communication paths. These same paths may have guided their raids and expansions deeper into France and beyond.
By the 840s, as evidenced by the coins found around the Irish Sea, the Vikings had gone beyond merely exploiting this network—they had co-opted it entirely. They integrated into the existing trade systems, controlling and profiting from the movement of goods such as silver, salt, and other high-value commodities. The silver deniers of Charles the Bald serve as markers of this transformation, revealing how the Vikings transitioned from raiders to power players in the economic systems of the early medieval world.
This reexamination of the evidence reframes the Viking Age as not solely an era of disruption but also an opportunistic adaptation. The Vikings did not build their trade networks in isolation; instead, they tapped into and eventually dominated systems laid down by others—particularly the Irish monastic communities. Their early raids on Lindisfarne, Ireland, and Noirmoutier highlight this strategic approach, where violence and commerce intersected to reshape the medieval world. The silver coins unearthed around the Irish Sea provide a glimpse into this complex and evolving relationship, marking the Vikings’ transition from outsiders to integral participants in a preexisting exchange network.
The Coin Finds: Mapping the Network
The silver denier discovered in Puddington, Cheshire, was unearthed in 1993 and is currently held at the Grosvenor Museum in Chester. This coin provides tangible evidence of the far reach of Carolingian silver into what is now northern England. Similarly, the discovery of an identical coin at Llanbedrgoch in Anglesey, found during excavations in the 1990s, is held by the National Museum of Wales. Llanbedrgoch is known for its Scandinavian connections, making this find particularly significant in linking the Irish Sea trade to broader networks. Finally, the inclusion of similar coins within the Cuerdale Hoard, discovered in 1840 along the River Ribble in Lancashire, now housed in the British Museum, adds another layer to this narrative. The hoard is one of the largest Viking-era silver hoards ever found, containing over 8,000 items, including ingots and coins.
Theories surrounding these findings suggest that the circulation of Melle-minted coins reflects robust trading activity between the Irish Sea and the Bay of Biscay during the Viking Age, likely centered on high-value commodities like wine, salt, and precious metals. These coins also hint at the integration of Viking trade into earlier networks established by monastic communities. While they do not directly prove monastic trade before the Viking Age, their presence strongly suggests a continuation and expansion of these routes, which Vikings may have exploited for commerce and raiding.
The Monastic Trade Network: Bridging the Bay of Biscay and the Irish Sea
Long before Norse longships plied these waters, the Irish monastic network had laid the foundation for transregional exchange. Irish monasteries, known for their scholarship and missionary zeal, were among the most influential institutions in early medieval Europe. These religious centers spread Christianity and facilitated trade, acting as hubs of economic activity.
One key player in this network was the Monastery of St. Philbert on Noirmoutier, a small island off the coast of western France. Founded in the early 8th century by St. Philbert, this monastery was deeply rooted in the Irish monastic tradition of St. Columban. It thrived on salt production, a valuable commodity that became central to its trade activities.
Irish Monasticism and Its Spread
The Columban tradition of monasticism, named for St. Columban, originated in Ireland and emphasized asceticism, scholarship, and missionary work. Irish monks, driven to spread Christianity, established monasteries across Europe. Luxeuil Abbey in present-day France was a notable center founded by Columban in 590. From Luxeuil, the Columban tradition radiated outward, influencing the foundation of numerous monasteries, including St. Philbert’s.
Irish monks brought with them not only their faith but also a culture of trade. Monasteries exchanged manuscripts, relics, wine, and other goods. The connection between Ireland and France was further cemented through these networks.
St. Philbert and the Irish Connection
St. Philbert’s story epitomizes the deep connections between Irish and Frankish monasticism. Born in the Frankish kingdom, Philbert followed the Columban tradition at Rebais Abbey, a monastery influenced by Irish practices. Inspired by Columban’s teachings, he established his monastery on Noirmoutier, blending Irish asceticism with Frankish monastic customs.
Noirmoutier’s salt production became a key economic driver. The Vita Philiberti, the saint’s hagiography, even records an instance of a ship laden with salt departing from Nantes, destined for Ireland. This small detail underscores the reality of trade between Noirmoutier and Irish monasteries, where salt was essential for preserving food and supporting local economies.
The Vikings and the Monastic Network
By the late 8th century, Viking raids began disrupting this network, but there is a strong argument to be made that the Norsemen initially followed the paths laid out by Irish monks. Monastic sites, rich in wealth and centrally located, were natural targets for Viking raiders. However, it is equally plausible that these routes guided the Vikings. The path from Lindisfarne to Ireland and then to the Bay of Biscay could have been discovered by Norse traders in the years preceding the first raids or followed by raiders, offering them access to established trade networks and resources such as Noirmoutier’s salt.
The raid on Noirmoutier in 799, just six years after the infamous attack on Lindisfarne in 793, suggests that the Vikings were not randomly targeting isolated locations but following a well-established trade and communication network instead. This early use of monastic trade routes may have given the Vikings a strategic advantage in their subsequent raids and expansions.
Rediscovering a Forgotten Network
The connections between the Irish Sea and the Bay of Biscay may not have been created by the Vikings but by Irish monks and their Frankish counterparts. These early medieval pioneers may have established a network that spanned seas and cultures through trade, scholarship, and missionary work, laying the groundwork for the interconnected world that the Vikings later exploited and expanded.
The silver deniers of Charles the Bald, the monastic salt trade from Noirmoutier to Ireland, and the spread of Irish monasticism all point to a vibrant exchange between these regions. By exploring these links, we can better understand the Viking Age and the centuries that preceded it.
As we continue to study these networks, it may come to light that many Viking trade routes may have been inherited (or stolen) from their monastic predecessors. It is a topic worthy of further exploration and one that figures prominently in my research, the precis of which I have shared in the article titled
The Viking Island.