Berserker, or berserk, was a member of a group of Viking warriors who were noted for their strength and courage. Berserkers prepared for battle by working themselves into a frenzy, and they went into battle without armor. Some historians believe that berserkers were insane, but others suggest that the berserkers were affected by food that contained behavior-altering drugs. Their wild behavior gave rise to the term berserk, which is still used colloquially to describe a person who acts wildly.
The Vikings were a seafaring people from Scandinavia. During the period from the 700’s to the 1100’s, the Vikings conquered or looted parts of England, France, Germany, Ireland, Italy, Russia, and Spain. In many of these areas, they later set up trading centers. See Vikings.