This is a Dutch video about a medieval gem found in Dorestad.
About 800 AD, Dorestad was the biggest town in what is now the Netherlands; though it had only a few thousand inhabitants. Utrecht, though the only bishop of the Netherlands then lived there, had only 400 people.
Dorestad was important for international trade in textile, animal skins, slaves, hunting dogs, etc. On the banks of the river Rhine, many (for the time) ships visited it.