Historically, the Viking era began with the attack on Lindisfarne monastery in AD 793, and ended with the Battle of Stamford Bridge in 1066, when the English army successfully repelled the Viking invaders led by King Harald Hardråde.
The Vikings' seaworthiness and impulsiveness led to the development of new areas along the Norwegian coast, westward to Iceland, the Faroe Islands, Shetland, Orkney, Scotland, Ireland and Greenland. The Norwegian Vikings also discovered Vinland, present-day America, long before Columbus.
Before the first millennium, iron tools were introduced into agriculture and there was a shortage of land to cultivate. During the same period, the King's power increased and he demanded large taxes from the population. Many emigrated to seek fortune and freedom, and pillaging became an alternative source of income.
Effective sailing ships and weapons made the Vikings a feared people amongst contemporary Christian Europeans. However, the image of the Vikings as bloodthirsty, savage plunderers do not tell us the whole story. The Vikings were also involved in a wealthy merchant trade, not only in Europe but also including the Byzantine Empire and the Baghdad Caliphate.