It has been common in all societies, that every person was characterized with a name. Often with multiple syllables/parts. Besides a social function, naming often had a religious function; christening is one example.

All people have a personal name or a first name. Most societies have found it necessary for people to have a nickname, surname or family name.

The largest group of personal names are the ones that state a religious connection; Christine and Christopher proclaim the faith of the bearer; Hans, Joanne, Jens, Joanna, John, show back to the New Testament, and their shared point of origin is the Jewish name "Jehovah is merciful". In Denmark a piece of paganism is preserved with names as Thor, Tordis, Ingrid and Ingolf.

Another large group of personal names are the ones stating virtues and good characters. Richard and Rikke are both mighty, the boy in addition ruthless, the girl in addition inoffensive. Most of these names are in Danish so worn, that the original meaning no longer is visible.

The third group of personal names are the ones that originally were nicknames/bynames, but were passed on through naming. Today only nicknames are in use, but several first names and most surnames started as nicknames/bynames. Names as Carl and Lauge first occurred as describing nicknames. A large group of names tells where the bearer lives - Østergaard (Eastern Farm), Skov (Forest/Wood) - or comes from - Finn, Flemming, Friis, Hamburger. Another group describes his occupation or position - Smed (Smith), Bager (Baker), Møller (Miller), Præst (Priest). Many names in the last 2 groups were decorated with more "distinguished" spelling - Schou and Schmidt - or translated into a more "distinguished" language e.g. Latin - Paludan for Kjær (Pool), Fabricius for Smed (Smith)

However among the largest group of surnames are patronymic, i.e. derivations of the father's name/first name - e.g. father's first name plus the addition "- datter" (daughter of ...) and "-søn/-sen" (son of ...). The addition "-søn/-sen" is widely spread; Danish "-sen", Scandinavian and English "-son", German "-s", Irish "O'-", Scottish "Mac-". Corresponding derivations from the mother's name are rare; e.g. in Danish, Svend Estridsen (Danish Viking king. His mother was Estrid, a Danish princess, his father was a duke).

Originally most family names were nicknames, but some were invented freely, sometimes randomly by joining syllables without meaning; the last ones are common in Denmark because of name-changes.

It was the nobility of the Middle Age that took up inheritable family names; mostly the name of the family manor - from this, in French "de", in German "von", in English "of". In Scandinavia, where feudalism never really was a hit, people took up an original personal byname - Hvide (White) - or names that described the heraldic mark of the family - Rosenkrans (Rosary). From 1526 all Danish noble families were bearing inheritable family names by order of the Danish king Frederic 1st. Women kept their family names in marriage - Lady Birgitte Gøye Herluf Trolle's (-wife, her husband being Herluf Trolle). Clergy and townsmen/citizens followed the adoption of family names, and eventually even the peasants followed. But the use wasn't fixed, and patronymic was often inserted. Therefore it had a very unfortunate impact when the Danish king Frederic 6th in 1828 ordered, that family names should be fixed, by having the children christened with the, for the present, used nickname/byname/surname.

All though common people protested, especially after the tightening of the legislation in 1856, patronymic was made into inheritable family-names, and the Danish name-pool became oppressed by the numerous Jensens (8%), Petersens and Hansens (6%). In 1904 the legislation was remedied by allowing the change of name, and the change of name(s) has been made easier by subsequent name-laws.

(extract from Lademann's Encyclopaedia (Danish)