Icelanders have no family names like ours. Everyone is the "son" or "dottir" of his/her father. Thus if a man named Olaf had sons named Sven and Olaf and a daughter named Ingrid, they are known as Sven Olafson, Olaf Olafson, and Ingrid Olafsdottir (which she keeps when married). If Sven Olafson marries Sigrid Petersdottir, they would have children known as Peter Svenson and Anna Svensdottir. Since there are not a huge number of names in use, a lot of people have the same name, and you can't tell who is related to whom without knowing the people and their families. Apparently the Iceland telephone book is a real bitch.