The Vikings are well known for the attacks they made against their European neighbours. But the Viking expeditions involved much more than violence, murder and plundering. In reality it was not them who “invented” raiding. To travel abroad and ravage foreign territories was not a new phenomenon – it had been done previously. But in the Viking period the raiding expeditions became more organised and frequent. Even though it required great investment in, for example, ships and men, it could be a profitable ”business” for the Vikings to go on expeditions. These expeditions varied considerably and the Vikings acted in many different ways. They could be traders, mercenaries, robbers, diplomats, blackmailers, explorers, immigrants, settlers, the military upper class or attackers.
The increased traffic on the sea also led to growth of the trading centres on land, particularly Hedeby and Ribe. A flow of trading products from foreign areas, such as the outermost Arctic North and the Islamic empires of the East, passed through the Viking markets. This contributed to economic development and town after town springing up in Denmark.