Imagine a Danish village in the early 1800-hundreds. You would have Niels the butcher and Niels the miller and Niels the shoemaker. At that time they would all baptize their children with the same surname. They did that, because then children were given the name of the father added -sen for son or -datter for daughter as their surname. So Niels would name his son Nielsen and daughter Nielsdatter. It was hard to know who was related to who by looking at their names since many were called the same. And further, Niels’ grandson would be named after his father and thus have another surname. That was confusing!
In 1828 the government tried to make it more see through by saying that children should be baptized with a family name which the family should keep for generations. That way Niels’ son and grandson and great grandson would carry the same name. It took around 40 years for the country population to adopt the law and give up the tradition with patronymic name giving. Throughout Danish history women have been given the surname of their father and after that take the name of her husband upon marriage. Until 1904 a woman had to apply for a licence to take back her maiden name after divorce. Today many women keep their maiden name in marriage.
Today still, the most used surname in Denmark is Hansen, then Jensen and then Andersen, preserving the legacy. On place number 19 you find the first surname not ending on -sen, that is Møller. In the late 1800-hundreds it became possible to change the family name to the nickname carried by one’s father and grandfather. Møller, for example, means miller, Søndergaard refers to the southern farm and Østergaard to the eastern farm.
So if you ask for a Danes’ surname, there is a great chance that it actually means something – go ask!