Until the late nineteenth century, patronymic naming conventions were common in Scandinavia, Wales, and a number of other countries. In fact, patronymic names are still used in Iceland. Now Denmark is returning to the tradition of their forefathers.
By way of explanation, patronymic naming is the practice of creating last names from the name of one's father. For example, Robert, John's son, would become Robert Johnson. Robert Johnson's son Neil would become Neil Robertson. Patronymic names are a problem for genealogists; tracking a family tree is most difficult when the surnames change every generation.
Starting next April, Danish newborns will no longer be required to share a last name with either of their parents. A new law allows a return to the Viking tradition of patronymics. Instead of maintaining a single last name across generations, in this system each generation of children is given a last name that consists simply of the father's or mother's first name with the suffix "son" or "datter" (daughter) added on.
Patronymic names were the only names used in Denmark from Viking days until 1828, when it was banned by law. The reason was simple: public authorities were having difficulties tracking people. These "public authorities" included tax collectors, the military draft boards, and the public education system. The 1828 law simply froze the process, dictating that new generations would keep the patronymic of the head of the family at that time. The unfortunate result was that two thirds of Danes still carry a limited selection of names such as Nielsen, Jensen, and Hansen.
For instance, both the former prime minister and current prime minister have a surname of Rasmussen. Foreigners often wonder whether they are related. They aren't; they're just Danes.
Of course, in these politically-correct times, the old traditions are being modified a bit. In the "old days," a baby's surname always reflected the father's first name. The new law allows for naming a child after the mother's first name by adding "datter." In addition, the new law allows for other forms of nomenclature, including Tamil and Arabic patronymics and Slavonic traditions of gender-specific suffixes such as -ski for men and -ska for women.
The primary reason for allowing people to go back to the old Viking methods was computers. It seems that there are so many Johnsons, Hansens, and Rasmussens in Denmark that keeping track of people by names is impractical. Instead, everyone has a number, somewhat similar to the Social Security numbers used in the United States. Computers can easily track unique numbers; so, everyone in Denmark is already tracked that way in computer databases. With no need to use any particular naming convention, the country is now free to revert to the methods of their horned-helmeted ancestors.