"A patronym, or patronymic, is a component of a personal name based on the name of one's father, grandfather or an even earlier male ancestor. A component of a name based on the name of one's mother or a female ancestor is a matronym. Each is a means of conveying lineage."
In Norse custom patronyms and matronyms were formed by using the ending -son (later -søn and -sen in Danish and Norwegian) to indicate "son of", and -dóttir (Icelandic -dóttir, Swedish and Norwegian -dotter, Danish and Norwegian -datter) for "daughter of". This name was generally used as a last name although a third name, a so-called byname based on location or personal characteristic was often added to differentiate people and could eventually develop into a kind of family name. Some Early Modern examples of the latter practice, where the patronymic was placed after the given name and was followed by the surname, are Norwegian Peder Claussøn Friis, the son of Nicolas Thorolfsen Friis (Claus in Claussøn being short for Nicolas) and Danish Thomas Hansen Kingo, the son of Hans Thomsen Kingo. Eventually, most Nordic countries replaced or complemented this system with the prevailing "international" standard of inherited family names. In Norway, for example, the parliament passed a family name act in 1923, citing the rising population and the need to avoid the confusion of new last names in every generation. The law does allow a person to retain a patronymic as a middle name in addition to the surname, as was common in Early Modern times; this is not a common practice, but does occur, a modern example being Audhild Gregoriusdotter Rotevatn). In Iceland, however, patronymics are still used as last names and this is in fact compulsory by law, with a handful of exceptions.
- The Norway Heritage Page on Norwegian names
- Diana Gale Mathisen's page on Scandinavian patronymics
- John Føllesdal's article on Scandinavians patronymics