Denier - Charlemagne Dorestad

Dorestad, on the Rhine delta near modern Wijk bij Duurstede, was the most commercially active port in the Carolingian world — a hub through which Frisian traders moved English wool, Rhenish wine, and Scandinavian furs. Charlemagne's monetary reform of 793–794 abolished the older lightweight denier and mandated a heavier silver standard, and Dorestad's mint was among those immediately pressed into producing the new coinage precisely because of its volume of cross-channel trade.

The site was repeatedly sacked by Viking raiders from 834 onward, effectively ending its role as a mint town within a generation of these issues.