Some Theory Introduction You may wonder why people from Spanish speaking countries have such long names. In Portuguese speaking countries also use two family names, but for them the mother's surname comes first. In my opinion this is better because you know for certain who the mother is, but in some cases one may not be so sure about the father. As you see, Spain has always been regarded as a country ruled by machos , but we respect more the women's dignity in this sense. Compound Surnames Well, things can get more complicated.
People sometimes merge their family names, creating compound names .
Another source of multiple-word surnames is the use of prepositions and conjunctions. This was useful when there were compound surnames and one can not tell where does the second surname begin. Traditionally one of the names had to be the Saint of the Birthday. This specially true for women. This is why most women use the other first name or a nickname.