Vikings
In England the Viking Age began dramatically on 8 June 793 when Norsemen destroyed the abbey on the island of Lindisfarne. The devastation of Northumbria's Holy Island shocked and alerted the royal courts of Europe to the Viking presence. "Never before has such an atrocity been seen," declared the Northumbrian scholar Alcuin of York. Medieval Christians in Europe were totally unprepared for the Viking incursions and could find no explanation for their arrival and the accompanying suffering they experienced at their hands save the "Wrath of God". More than any other single event, the attack on Lindisfarne demonised perception of the Vikings for the next twelve centuries. Not until the 1890s did scholars outside Scandinavia begin to seriously reassess the achievements of the Vikings, recognizing their artistry, technological skills, and seamanship.
Denmark
From the 8th to the 10th century the wider Scandinavian region was the source of Vikings. They colonised, raided, and traded in all parts of Europe. The Danish Vikings were most active in the eastern and southern British Isles and Western Europe. They conquered and settled parts of England (known as the Danelaw) under King Sweyn Forkbeard in 1013, and France where Danes and Norwegians founded Normandy with Rollo as head of state. More Anglo-Saxon pence of this period have been found in Denmark than in England.
Denmark was largely consolidated by the late 8th century and its rulers are consistently referred to in Frankish sources as kings ("reges"). Under the reign of Gudfred in 804 the Danish kingdom may have included all the lands of Jutland, Scania and the Danish islands, excluding Bornholm.
The extant Danish monarchy traces its roots back to Gorm the Old, who established his reign in the early 10th century. As attested by the Jelling stones, the Danes were Christianised around 965 by Harald Bluetooth, the son of Gorm. It is believed that Denmark became Christian for political reasons so as not to get invaded by the rising Christian power in Europe, the Holy Roman Empire, which was an important trading area for the Danes. In that case, Harald built six fortresses around Denmark called Trelleborg and built a further Danevirke. In the early 11th century, Canute the Great won and united Denmark, England, and Norway for almost 30 years with a Scandinavian army.