Rollo. Vikings. The "real" Rollo invaded France, attained lands and became the first Duke of Normandy. His descendent, William the Conqueror, invaded England and his lineage were then the Kings of England.
Viking painting Viking berserks are described as terrible in the Icelandic old Sagas. They are supposed to have trembled, clapping their teeth and howling. When attacking they would bite their shields (Beauty Women Hot)