The first recorded Viking raid was an AD 793 surprise attack on the monastery of Lindisfarne, England. The raiders looted the monastery, killed any monks who got in the way, then loaded up their ships and sailed home to Scandinavia. Within 100 years, they were sailing all the way to the Mediterranean to attack Italy and sailing down the Volga to raid the Black Sea.
"I have, in all, the death-stroke given to foes of mine at least eleven; Two more, perhaps, if I remember, may yet be added to this number, I prize myself upon these deeds, my people such examples needs. Bright gold itself they would despise, or healing leek-herb underprize, if not still brought before their eyes." King Harald Hardraade