The mid-10th-century reign of Harald Bluetooth as king of a newly unified, powerful and Christianized Denmark marked the beginning of a second Viking age. Large-scale raids, often organized by royal leaders, hit the coasts of Europe and especially England, where the line of kings descended from Alfred the Great was faltering. Harald’s rebellious son, Sven Forkbeard, led Viking raids on England beginning in 991 and conquered the entire kingdom in 1013, sending King Ethelred into exile. Sven died the following year, leaving his son Knut (or Canute) to rule a Scandinavian empire (comprising England, Denmark, and Norway) on the North Sea.
After Knut’s death, his two sons succeeded him, but both were dead by 1042 and Edward the Confessor, son of the previous (non-Danish) king, returned from exile and regained the English throne from the Danes. Upon his death (without heirs) in 1066, Harold Godwinesson, the son of Edward’s most powerful noble, laid claim to the throne. Harold’s army was able to defeat an invasion led by the last great Viking king–Harald Hardrada of Norway–at Stamford Bridge, near York, but fell to the forces of William, Duke of Normandy (himself a descendant of Scandinavian settlers in northern France) just weeks later. Crowned king of England on Christmas Day in 1066, William managed to retain the crown against further Danish challenges.