England enjoyed a respite from Viking attacks until 980, when raids from Denmark and the Norse settlements in Ireland and Scotland began.
England's King Aethelred II was a poor war leader who was soon reduced to paying Danegeld to buy off the Viking raids. Among the leaders of the Vikings were Olaf Tryggvason, who used the proceeds of the raids to win control of Norway in 995, and the Danish king Svein Forkbeard. As the English defences collapsed, Svein's objective changed from exacting tribute to outright conquest. At the end of 1013 Aethelred fled the country and Svein was accepted as king of England, but he died in a matter of weeks before he could consolidate his conquest. England had to be reconquered, after an epic struggle with Athelred's son, Edmund Ironside, by Svein's son, Cnut, in 1016. Though many Danish aristocrats were granted English lands, Cnut's conquest was not followed by any significant rural settlement. Under Cnut England became part of an empire that included most of Scandinavia, but his successors showed none of his ability and the native dynasty was restored in 1042.
The Norweigian king Harald Hardrada attempted to conquer England in 1066, but was crushingly defeated at the battle of Stamford Bridge, fatally weakening the English just weeks before William the Conqueror led his successful invasion from Normandy. The Danes supported rebellions against William in 1069-70 and 1075, and Cnut II planned another invasion in 1085. Disputes prevented the fleet from sailing, however, and Cnut's assassination in 1086 effectively marked the end of the Viking Age in England, though the Norwegian king Harald Eystein led a plundering raid along the east coast as late as 1153.
Notes from Encyclopaedia of the Viking Age by John Haywood. Thames & Hudson 2000. pp64-65