The Viking Rollo was a real person. In a 911 treaty he received the French City Rouen and surrounding lands. In return he and his warriors would defend the area and were baptised as Christians. The area became known as Normandie, the land of the Northmen.
Although there were other designs, this is the typical viking house design called the Trelleborg House. This is a reconstruction of the Trelleborg Houses found at the Trelleborg Viking Fortress near Slagelse in Denmark.