On 8 June 793 Norse raiders descended on the holy island of Lindisfarne off the northern English coast, plundered the monastery, killed or enslaved monks, and carried off centuries of accumulated manuscripts and treasure. The event sent a deep shock through Europe — a letter by Alcuin, then at Charlemagne's court, captures the continent's horror vividly.

The Viking Age is conventionally dated from this raid, but the phenomenon was more complex. Scandinavians — from what is now Norway, Denmark, and Sweden — had developed extraordinary ships, shallow enough to enter rivers and seaworthy enough to cross open ocean. Combined with population pressure and political fragmentation at home, this technical advantage gave them a remarkable mobility: as raiders, traders, settlers, and mercenaries.

The range they covered over the next three centuries is astonishing: Ireland (where they founded Dublin), England (Jorvík), France (Normandy), Iceland, Greenland, and even Newfoundland at L'Anse aux Meadows — the only confirmed evidence of a European settlement in the Americas five hundred years before Columbus. To the east they descended the river systems of Russia and traded with Byzantium and the Islamic world. The Viking Age closed in the mid-11th century with the Christianisation and political consolidation of the Scandinavian kingdoms.