I am currently researching the ancestry of this profile under discussion, who is the mother of the famous St. Francis de Xavier.
It shouldn't be very difficult, or at least not impossible, in that both she and her husband were aristocracy, and she came from a noble family of royal descent.
The hardest part is that the available records are in Spanish, not my first language and not one in which I am at all fluent. Some of it is likely also in Latin.
Also the history of the Basque region has occasionally born the strain of fierce political and religious struggles ranging over a long period of time (centuries).
But I enjoy learning about Castle Javier (aka Xavier) and suspect there's a lot more to the story than I've heard so far.
Martín de Azpilcueta Jaureguízar, Señor de Azpilcueta is not her father, and I don't believe he was ever married at all. I haven't seen any such evidence. I think he just got conflated with her father who shared the same given name, "Martin".
My initial source (and there are many more given in citations here and elsewhere) is "Monumenta Xaveriana, ex autographis vel ex antiquioribus exemplis collecta" by St. Francis Xavier (1506-1552); and Alessandro Valignano (1538-1606), of which my copy was published in 1899; and the book is at least partially an attempt to preserve for posterity the Xavier family history as relevant to the life of St. Francis.
The de Xaviers descended from or 'converged' from the Atondo, Jasso, Aznarez, and Azpicuelta families and their ancestors.
I believe Martín de Azpilcueta Jaureguízar, Señor de Azpilcueta comes from a related but separate branch of their tree. A cousin perhaps. "Lords of Jaureguiçar" is only mentioned once, on page 671 (paragraph 11, bottom of page) of this more than a thousand page tome, where a Pedro de Jaureguiçar, lord of Jaureguiçar, is included in a list of people given in a testimony by Martín de Azpilqüeta (age 47 in 1614, so born ca. 1567), as one of many over his lifetime from whom he had heard things spoken about the respected priest.
In this particular sworn testimony which was conducted in March of 1614, no kinship is specified relevant to Pedro de Jaureguiçar, although we can assume he was at least extended family. Pedro died at age 76, ten years before the recorded "interrogation" of Martín de Azpilqüeta ... whose palaces are M[ ¿? ]... So this Pedro died ca. 1604 and was born ca. 1528.
Miguel de Azpilqüeta who died 14 years prior (ca. 1600) at age 60 (b. ca. 1540), is listed specifically as the father of the witness.
And the name of this witness' grandmother was María de Garinoayn. She died 30 years prior (d. ca. 1584), at age 88 (b. ca. 1496).
Another name on this witness' list is "Doctor Navarro," aka Martín Salvador de Azpilqüeta, who was a doctoral canon of the holy church of Toledo, and would have been seventy-two years old when he died (b. ca. 1525), and he died seventeen years ago (d. ca. 1597).
It is important to bear in mind that all but one or two of the children of Juan de Jasso y Atondo and María de Azpilcueta y Aznárez received their mother's surname (Azpilcueta) to signify their inheritance of her estates.
As lord of castle Javier, only Francis, the youngest born and heir of the castle, was known as "de Xavier". He probably favored the French form "Xavier" after moving to France where he was educated and met his mentor, Loyola. The castle eventually ended up in possession of the Church after his death. However, apparently some of his fraternal nieces and nephews were also known by the name "de Xavier".
Well that's a start. And I'm thinking their must be a good reference for both the Azpilqüeta and Aznarez families, in that they were presumably high nobility at least partly descended from royalty. I'm only beginning to look into that now, and it may take awhile to figure it out. I've already come across some tantalizing clues, lol.
https://archive.org/details/monumentaxaveria432fran/page/671/mode/1up
