In the 9th and 10th centuries, the Vikings raided the largely defenceless Frisian and Frankish towns lying on the coast and along the rivers of the Low Countries. Although Vikings never settled in large numbers in those areas, they did set up long-term bases and were even acknowledged as lords in a few cases. In Dutch and Frisian historical tradition, the trading centre of Dorestad declined after Viking raids from 834 to 863; however, since no convincing Viking archaeological evidence has been found at the site (as of 2007), doubts about this have grown in recent years.

One of the most important Viking families in the Low Countries was that of Rorik of Dorestad (based in Wieringen) and his brother the "younger Harald" (based in Walcheren), both thought to be nephews of Harald Klak. Around 850, Lothair I acknowledged Rorik as ruler of most of Friesland. And again in 870, Rorik was received by Charles the Bald in Nijmegen, to whom he became a vassal. Viking raids continued during that period. Harald's son Rodulf and his men were killed by the people of Oostergo in 873. Rorik died sometime before 882.

Viking raids of the Low Countries continued for over a century. Remains of Viking attacks dating from 880 to 890 have been found in Zutphen and Deventer. In 920, King Henry of Germany liberated Utrecht. According to a number of chronicles, the last attacks took place in the first decade of the 11th century and were directed at Tiel and/or Utrecht. These Viking raids occurred about the same time that French and German lords were fighting for supremacy over the middle empire that included the Netherlands, so their sway over this area was weak. Resistance to the Vikings, if any, came from local nobles, who gained in stature as a result.