The First Domino: The Fall of Noirmoutier to the Vikings
A Deep Dive into the Viking Invasions of Western France — Episode 5
Last week, we examined the monastery of St. Philbert’s attempts in 830 to defend itself against what had been described as early as 819 as ‘frequent and persistent raids’ by the Vikings. This week, we will move forward a few years—though how many precisely is up for debate—to a most spectacular clash between the Franks and the Vikings. The episode shines a light on the difficulties the Carolingians faced in defending key economic nodes while the empire descended into political turmoil.
The castrum constructed in 830, along with the soldiers hired to defend it, did not appear to provide the monks with sufficient confidence to remain on the island of Noirmoutier during the raiding season. Instead, they appear to have continued their annual migration to their satellite priory on Grand-Lieu Lake. While the record on what happened thereafter is sparse, by 830, we start to see the chroniclers pick up where the cartularies, letters, and diplomas we relied upon for information up to then left off. Most pertinent among these for our exploration of the events of 835-836 are three primary sources that, together, give us an indication of the dire situation the monks of Noirmoutier faced.
First, we have the Annals of St. Bertin, which begin in 830 with a record of the challenges Emperor Louis the Pious faced with his sons. Louis was determined to bring the region of Brittany, then in open rebellion, back under the Frankish yoke. But his nobles refused to muster on his behalf. The chronicle continues to focus on the internal political turmoil that ensued until the entry for the year 836, when it mentions an attack by Northmen on the port city of Dorestad and the surrounding areas. The chronicler appears determined to highlight what a shock this event was to the Carolingian world, and a shock it was. Except, read on its own, we seem to be given the impression that this attack happened as a singular event.
The year 836 was a consequential one for Viking raids. Ermentaire of Noirmoutier recalls in his Life of St. Philibert witnessing a battle between the Franks and the Northmen on his island that summer. His testimony is confirmed by the Annals of Angoulême, which relay to us that the count of Nantes, Renaud, whose name is written as Rainald in the Annals of St. Bertin, mobilized an army to defend the island in 836. While there is a disagreement in the dates for the event, we can say with a certain degree of certainty that the events evoked took place.
Between the two testimonies, we may deduce that a Frankish army indeed traveled to the island during raiding season and successfully made contact with a Viking fleet. They fought a battle in front of the castrum, and the Franks won the day. According to Ermentaire, his patron saint assisted the Franks in the fight by frightening the Northmen in a ghostly form, allowing the Franks to rout their enemy with no casualties on their side. The Annals of Angoulême provide a dryer account, but support the idea that the battle was an overwhelming victory for the Franks.
Victorious, the Franks returned to Nantes, assured that the Northman scourge had been neutralised. Except, it hadn’t. Both sources report that another fleet arrived in the autumn and retook possession of the castrum. The monks fled once more, but this time, they never returned. Ermentaire writes for the year 836 that the order of St. Philbert definitively abandoned the island.
What do the raid on Dorestad and the battle on Noirmoutier have to do with one another? Perhaps nothing. But together they may paint a broader picture of Viking activity in France in the early 830s, and even the 820s. The raid on Bouin happened after the fleet that sacked it had been repelled in Frisia. Is it a coincidence, then, that the battle on Noirmoutier and the raid on Dorestad occurred around the same time? Or are we seeing the continuation of a pattern ratcheting up in intensity?
Current scholarship does not yet connect the two. They are both considered to have been part of Lucien Musset’s proposed first phase of Viking expansion, termed ‘sporadic raiding,’ implying that there was no discernible pattern behind the raids other than finding a gap in the Carolingians' defenses. While this notion is true to a significant degree, I believe the confluence of these two events supports the idea that the Vikings were much more organized and intentional about their approach to the Frankish realm than previously recognized in the first three decades of the so-called Viking Age. See my article on the Vikings and salt.
In any case, the year 836 marks the beginning of the ‘established’ timeline for Viking activity in the Carolingian empire. As we will see next week, once Noirmoutier fell, so too did the gates of Hel (mispelling intentional) open for the Franks.
The final act of my novel, The Lords of the Wind, is, in fact, based upon the battle of 835-836.
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Author Update: An Award-Winner Once More!
The Fell Deeds of Fate, the fourth installment in my Saga of Hasting the Avenger, just won a bronze medal with the Reader’s Favorite Book Awards 2025! This comes on the heels of The Fell Deeds of Fate becoming a top-recommended book through Kirkus Reviews.
It’s days like these that I think maybe, just maybe, I’m doing something right.
This is my second Reader’s Favorite Award. The Lords of the Wind took home the gold medal in 2020.
And, as always…
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