First, my apologies if the title has any sort of ahistorical connotation, I was just trying to keep my wording concise. I’ve been listening to a podcast on the history of Ireland, and the host, Fin Dwyer, talked about how Charlemagne’s grasp on the northern French coast made peaceful trading with the outposts and towns impossible, so Scandinavians resorted to raiding more often. He mentions it relatively offhand, so I’m not sure how much stock to put into it, but I was just wondering if there’s much in the record about the shift from peaceful traders to internationally feared raiders. Thanks in advance!
This doesn't really pass muster for me. Charlemagne was able to make some monetary reforms and impose tolls. This probably meant that traders visiting some towns on the Frankish shores needed to convert their wares to cash to pay taxes, and it gave an opportunity for money-changers or minters to embezzle a bit on the side. But it seems like a stretch to assume that Charlemagne (or his successors) could exert much more control, or that they'd want to. I for one don't follow the logic that Charlemagne would—even if he could—strangle trade to the point that foreign traders would opt to raid instead. I can't imagine what his motivation would be.
Furthermore, the timing and geography of viking raids are off. Charlemagne ruled until his death in 814. By that point, viking raiders were operating along the shores of Britain and Ireland, and they were working their way south along France's Atlantic shore. Alcuin wrote a letter about raids on Aquitaine in 799, the Royal Frankish Annals note these events in 800. Frankish sources are otherwise pretty silent during Charlemagne's reign.
I hesitate to make an argument from this silence, but when viking raiders hit Dorestad in 834, it made a big splash. Part of the reason for this is that writers in the 830s were working under Louis the Pious, who seems to have held a looser hold over what was being written. Whereas the Royal Frankish Annals had been written under Charlemagne's watchful eye, the Dorestad raid was recorded in the Annals of St-Bertin and the Annals of Xanten, which were no longer directly connected to the royal chapel. That might help explain their willingness to record events on Frankish trading towns on the North Atlantic, but their shock still seems authentic.
So I'm dubious for a few reasons. I don't think that Frankish rulers had enough control over trade to strangle it, or the motivations to do so. Early raids didn't target the trading towns that Scandinavians had supposedly been cut out of. And the monasteries and church communities they hit throughout the British Isles and along France's Atlantic shore seem like poor places to collect the kinds of things that had been available in places like Quentovic and Dorestad.