added by archaeologs A Germanic people inhabiting the North Sea coastal plain and islands between the Rhineland and the Elbe (Frisia) in the early centuries BC and AD. Their coastal settlements were on artificial mounds known as terpen. The Frisians were involved in the invasion of England by the Anglo-Saxons in the 5th century AD. They controlled the trade of the North Sea from the port of Dorestad at the mouth of the Rhine, which became a target for Viking raids. Frisia was absorbed into the Frankish kingdom, its conquest being completed by Charlemagne. Archaeological evidence of these trading ventures is seen at Dorestad, where extensive excavations have been done. Evidence in the mounded villages show signs of long-distance trade contacts, suggesting that the Frisians linked the Rhineland to the northern world from the beginning of the Roman period until modern times.