Anglo patronymics can go even further afield –
Aitken - son of Adam
Hancock - son of John
Hodgekiss - son of Roger
Saunders - son of Alexander
Dobbins, Hobbes - son of Robert
Whatley - son of Walter
I thought the -s names were typically Welsh. Though it isn’t too surprising since they do speak English there, too, mostly.
Wikipedia in general is great at explaining questions like this. There’s an entry for just about every common surname in the more widely spoken languages.
So I did know that Sanchez means “son of Sancho”, but I can’t say I’ve ever known of a person named Sancho, except for early Spanish kings.
Perhaps because no one wants to be likened to “Sancho Panza” (Sancho Beer-gut) in Miguel de Cervantes Saavedra’s Don Quixote de la Mancha?
Also, in Mexico, “El Sancho” is slang for the married woman’s lover who sneaks into the house once the husband has gone off to work or if the husband is in jail. Interesting discussion on “el Sancho”: el sanchez/el sancho | WordReference Forums
I think “Pere” is the Catalan equivalent of Pedro (Peter); compare French “Pierre”.
The Welsh picked up the -s from the English. Names like Jones, Davis, Williams, Edwards, Hughes, Richards, etc., could be held by people with either Welsh or English ancestries. But etymologically, these are English names.
Welsh patronymics are formed from the P-Celtic form of “mac” – “map” or “mab.” Thus –
Upjohn, Bevan, Bowen (Evans) - son of John
Pulliam - son of William
Pugh - son of Huw
Powell - son of Hywel
Penry, Parry - son of Henry
Price - son of Rhys
Pritchard - son of Richard
Prothero - son of Rhydderch
Prosser - son of Rhossr
Proger - son of Roger
Probert, Probyn - son of Robert
Names beginning with “Fitz-” (Fitzpatrick, Fitzgerald, etc) are also “son of” names. I vaguely recall reading that bastard sons of monarchs were saddled with these in particular.
According to Wikipedia, Sancho is a name of Basque origin, but it also says “citation needed”. To anyone who knows, is that accurate? I cannot think of any known Latin or Germanic name that looks like Sancho, so it makes sense that it come from a completely different language, but OTOH it could as well be Celtic or something else.
Similarly Díaz (Rather than “Dieguez”) is “son (or descendant) of Diego.”
Since Juan is such a common first name and I’ve never seen Juanez, I’m going to assume that Son of John is Juarez. Am I right?
I’d have assumed so, but here’s a site that suggests “no”, FWIW:
That site also mentions that Suarez and Juarez are thought to be variants of the same name.
A Celtic origin would seem perfectly reasonable, but there were other cultural influences in Iberia.
What about Arabic or Berber? Could the name be from the Moors?
Sancho is derived from Latin “Sanctius”-holy, as is the Italian name Santo/Santino.
I believe the Spanish patronym for “Juan” is “Juanico.”
I’ve doing some quick-&-dirty Googling … and I am surprised that I am having a hard time finding a Spanish cognate to “Johnson”. Interesting.
There can certainly be “holes” or “thin spots” in a language’s surname inventory, though. In English, a first name as common as “Mark” is matched to the rare patronymic, “Markson”. “Georgeson” and “Victorson” are out there, too, if uncommon.
This site suggests “Yañez” as Jaun’s “-ez form” patronymic.
With that information, Googling “Yañez” turns up lots of addtional cites. While I have heard of that surname, it doesn’t seem to be particularly common.
This sounds quite possible. Do you have a cite for it?
Not a good one. Wiktionary says so.
as does Wikiname, which pretty stupidly says in one sentence that the name is of Latin origin and then in the next that it “may be of Basque origin.”
http://wiki.name.com/en/Sancho#ORIGIN_AND_HISTORY
So take those sites for what they’re worth.
I don’t think there are really holes here. After all, in English a patronymic can be formed with no alterations whatsoever – Mark (or Marks), George, and Victor can by themselves operate as “son of Mark,” “son of George,” and “son of Victor.” I’m not sure how common they are, but I’m certain I’ve seen “George” and “Victor” used as family names.
Yeah … I went back in and added “thin spots” after doing a little research. I just meant “holes” and “thin spots” as a matter of frequency. But then, names tended to be unevenly distributed anway. Loads of “Johnsons” & “Smiths”, not very many “Marksons”.
There’s no “Dweezilsons” out there, are there? 
Ah, I see, I wasn’t counting “first-name” surnames like “George” or “Victor” as patronymics. Of course, they very well could have been father-derived names way back when.
Still, you’re absolutely right about the not-too-uncommon surname “Marks” – it’s built on the model of “Peters”, “Michaels”, “Richards”, etc.
Yeah, like Boy George!