Most Icelanders still follow the ancient tradition of deriving their last name from the first name of their father. If a man is called Leifur Eriksson (his name is Leifur and he is Eriksson, the son of a man named Erikur). A woman called Johanna Heraldsdottir has the personal name Johanna and is Heraldsdottir (daughter of Herald). If these two have a son, he would have Leifsson as a last name and their daughter would have Leifsdottir as her last name. These aren’t names as such, but patronymics, which refer to their fathers. Hard to track, but very important to call people by their given (first names) and not just their surnames. Many people have two or more given names and there are just a limited number of Icelanders who do have family names.