> From what I understand, if the genetic lineage is particularly elite, you might keep more.

You mean like Pablo Diego José Francisco de Paula Juan Nepomuceno María de los Remedios Cipriano de la Santísima Trinidad Ruiz y Picasso

Ironic that for all the elite lineage captured here, the one that he ended up stuck with is a very plebeian surname of non-hispanic (Ligurian) origin.

I would like to know more about the conditions under which Spanish family names became "X y Y" rather than "X" or "Y".

Inheriting both surnames is traditional, picking one is nontraditional or foreign. The interesting option is between using a conjunction or not (Paul Davis Thefirst or Paul Davis y Thefirst), which seems mostly a matter of sounding better or, as Wikipedia suggests, disambiguating between first names and surnames (if it precedes the conjunction it is a surname).

No, the surnames are Ruiz and Picasso.

The rest are given names and nobody uses more than two. It was in the baptism record where all the saints of the days used to be added. I have a similar record with a dozen names, but only two given names in the civil record, of which I only use the first.

Visions of Epic Rap Battles of History when you read it spelled out like that: https://youtu.be/WGN5xaQkFk0?si=aKCPFF_yfy6ly8Tb&t=61

A couple of years ago, in Argentina, my country, some idiot representative tried to create an actual law to force everyone to use the last name of both parents in strict alphabetical order.... and in the next generation, choose 2 out of 4 in strict alphabetical order, and in 10 generations everyone would have a couple of last names like aaaa aaab

Kirchner?! Hehe

It should be randomly selected and that would solve all the issues.

10 generations is plenty of time to develop a caste system that discourages intermarriage.

Yeah. I had to get a second last name when I was granted Spanish citizenship, which leads to my full name not matching my Argentinian ID. This generates (small) problems when flying between Spain and Argentina. Also partially due to my full now being too long to print on a boarding pass.

I love paperwork, so I always handle passport applications and stuff for us, and whenever I have to fill out my wife's stuff, there's that part about other last names, and I get super paranoid trying to remember which ones she's officially used (she doesn't even remember, or even have records sometimes due to the nature of immigrating), because between Latin America and the US pre- and post-citizenship plus getting married, it's kind of a nightmare to remember when there was a de something, an y something, or just one surname, or two surnames.

And then her parents are from another country with different surname rules, throwing a crazy wrench in things when she has to deal with her other citizenship documents, which adhere to that other country's rules.

> trying to remember which ones she's officially used

I had an uncle who was very proud of the fact that his birth certificate, passport, and the spelling he actually used for his first name all disagreed.

Slightly related story but, I too, found out my documents were out of wack when I applied for financial aid in college. I originally had two middle names at birth but then it was switched to only (the first) one a year or two later. My birth certificate had both names, my drivers license the first middle name, and my social security had the second middle name. It was a huge pain to get fixed, ended up just changing the two easiest to change to match the third.

Two names, two ids, two countries????

“Tax Agencies hate this one trick…”

> Two names, two ids, two countries????

Yup. Quite common with kids with one parent from a country using, say, the roman characters and another from an asian country (like say a France / Japanese mixed kid). If the (french) father goes to the french embassy or to France to declare the kid under one name and then the (japanese) mom goes to declare the kid with a japanese name, the kid literally has two identities. Not just two passports (which is highly common) but two identities.

In less common case it can happen with just the given name being different in two countries: I know a dude who as a Portuguese given name on his Portuguese passport and the french version of that name on his french passport. They're considered by the authorities to be two different persons and he already got into trouble (administrative stuff) so now he's careful.

Also note that it's a documented fact that for fraud there have been people caught declaring a kid that wasn't their: kid born at the hospital, quickly "rent" the kid to friends from the community, declare the kid as if he was born at home (by having a doctor come). Profit from welfare (in the EU) money due to the fact that you now "have" one more kid. One such case was uncovered when the doctor who gave birth to the kid was then sent later in the day to witness a "born at home" kid.

I'm sure there are other cases: the world is big.

Just FYI in English doctors don’t give birth to other people’s kids.

More specifically, for the verb “give birth to”, the mother is the direct object and their new born child is the indirect object. The verb “deliver” can have the doctor or midwife or so on as the direct object.

I am bringing this up because I had to read your comment several times before I realized it was a comment about language use rather than about the role of doctors in England.

Finally, to be completely pandemic, doctors can give birth to other people‘s kids. My wife, a doctor, gave birth to my sons; there was another doctor there who delivered them.

I believe you meant "pedantic" rather than "pandemic".

Actually a somewhat decently known way of avoiding tax on real estate transfers within the family in Japan is to move abroad, gift it, and then move back. The other way is gift it as a wedding gift, as wedding gifts (and others made out of customary social obligations) are not taxable over there.

A cool feature of the Spanish naming custom is that it can infinitely keep track of surnames. E.g., following @alricb's comment below, let's consider Pablo Picasso, who's name was Pablo Ruiz Picasso [1], after his father José Ruiz Blasco [2] and his mother María Picasso López. Surnames in the Spanish custom are concatenated with the following algorithm: father's first surname, mother's first surname, father's second surname, mother's second surname, and so on. In Pablo Picasso's case this would result in Ruiz Picasso Blasco López.

Or in Python:

```

from itertools import chain

fathers_surnames: list[str] = ["Ruiz", "Blasco"]

mothers_surnames: list[str] = ["Picasso", "López"]

kids_surnames: list[str] = list(chain.from_iterable(zip(fathers_surname, mothers_surname)))

```

Pablo Picasso's example is also a good way to touch upon your comment on how elites have used naming customs differently (I guess to distinguish themselves): Pablo's parents are listed in Wikipedia as "José Ruiz y Blasco" and "María Picasso y López", as opposed to the standard "José Ruiz Blasco" and "María Picasso López" (which I chose above). Similarly, Pablo was given the pompous birth name "Pablo Diego José Francisco de Paula Juan Nepomuceno María de los Remedios Cipriano de la Santísima Trinidad Ruiz y Picasso", instead of the more humble one (or maybe two) names that has been custom in Spanish.

Tangentially, I would say piling up names like this is more of a Catholic tradition than a Spanish one, e.g., the Archduchess Maria Theresa of Austria-Este, born Maria Theresia Beatrix Gaëtane, Erzherzogin von Österreich-Este, Prinzessin von Modena [3].

[1] https://en.wikipedia.org/wiki/Pablo_Picasso

[2] https://en.wikipedia.org/wiki/Jos%C3%A9_Ruiz_y_Blasco

[3] https://en.wikipedia.org/wiki/Archduchess_Maria_Theresa_of_A...