Some notes on family names.
As populations grew, it became necessary to identify people with more more than just one name. Sometime in the Middle Ages last names, surnames, became common. Often taken from occupations--Smith, Farmer, Miller--or physical attributes--Red, Long, Short (Green must have been a seasick sailor!), last names helped distinguish between Godwin the Miller and Godwin the Farmer, important distinctions when the government is out collecting taxes. As the practice of using last names grew, they became associated with families and clans, bonding individuals into identifiable groups.
In many cultures, the family name belonged to and followed the male line, with the wife assuming her husband's last name and the children of the marriage given their father's last name. This convention was far from universal, however.
Scandinavian surnames names used to be derived from their father's first name, suffixing the equivalent of son or daughter so that surnames would change from generation to generation. I don't have to go back too far in my family tree to find Ane Olava Nilsdatter, the daughter (datter) of Nils Johan Nilsen, or Johannes Olsen , son (sen) of Ole Johannesen. That naming convention changed when the Scandinavian countries passed laws requiring heritable names (consistent surnames passed from one generation to the next). Denmark passed naming laws in 1820, with Sweden following in 1901, and Norway in 1923. When required to adopt heritable surnames, families were not required to use any particular name. Many continued to use the name in use when the laws were passed, while others chose names associated with their farm, with their occupation, or whatever they felt would be a good surname. When Scandinavians immigrated to America, they were often at the mercy of the immigration officer who wrote down what ever he though he heard or what he could spell. Many immigrants also chose to Americanize there names to better fit in with their newly adopted country. For a much more in depth explanation check out What your Scandinavian name ending in son or sen means or Understanding Norwegian naming patterns.
While researching my wife Laura's Spanish heritage, I learned quite a bit about Spanish surnames and discovered that I have a lot more to learn. Surnames consist of two names, the first from the father and the second from the mother, occasionally connected with 'y' or 'e' (and). Traditionally, women did not change their names when they got married, although it has become common for the woman to suffix "de" and her husband's last name. Following form, their children's surnames would be a compound surname taken from their father and mother. Each generation the surnames would change. This method of changing surnames makes researching Spanish genealogy very difficult but once you have a person that you are sure is related and that you have the correct surname, you have a very good lead on both the father and mother. Using this form of father's first surname followed by mother's first surname, I'm pretty sure I have errors in my tree but these are the names that I have found and until finding more documentation, probably won't change them.
There are other variations to Spanish surnames. Each part of the surname can also be a compound name. An example given in a Wikipedia article:
"...the parts usually linked by the conjunction y or e (and), by the preposition de (of) or by a hyphen. For example, a person's name might be Juan Pablo Fernández de Calderón García-Iglesias, consisting of a forename (Juan Pablo), a paternal surname (Fernández de Calderón) and a maternal surname (García-Iglesias)." (Check out Widipedia's Spanish naming customs).
Typically, Spaniards do not have a middle name. Instead, everything before the surname is considered their given name, and that can be quite a lot. Unlike Scandinavian countries, Spain continues with their surname tradition and has laws specifying how surnames are implemented. There are some exceptions to the father-mother ordering of the surnames but any changes have to apply to all the children of the marriage. As Spanish populations immigrated to America, they encountered many of the same issues as other immigrants with the immigration officers not understanding or knowing how to spell the names they were told, that husband and wife didn't have the same surnames, and that Spaniards had (at least) two surnames. Usually the maternal surname was dropped; sometimes the paternal surname was mistaken for a middle name and the maternal surname became the family's surname in the US.
Post a comment if you know how other cultures did or now do surnames. Meanwhile, I am going to dig into Gaelic names and see how those differ and how they have changed over time.