One of my favorite personal discoveries in my genealogy journey has been a fellow in Australia, named Milton Baar. He introduced me to his own branch of the Pikholz family, a branch of which I had had no knowledge whatever. This was about ten years ago.
In time, and with the help of DNA, I was able to figure out that my second great-grandmother, Rivka Feige Pikholz, had a previous husband and that Milton's family was descended from that marriage. So he and I are half-third cousins.
Milton had mentioned that his wife had some Jewish ancestry, via her mother Esma Mathews whose family had come to Australia from England in the 1800s. He did DNA tests for his wife and her mother, including MtDNA, but I did not pay it much attention. Esma has over 350 matches of zero genetic distance with her MtDNA.
A couple of weeks ago, I saw that Esma has a match at a genetic distance of 1with a prominent east Galician researcher who had just done his MtDNA test. I pointed this out to Milton and he said that Esma's maternal grandmother was Matilda Mendoza, presumably of Sephardic Jewish descent.
Matilda is buried not far from Milton's house and he got me a photograph of her 1897 tombstone.
I reported back to him that Matilda's Jewish name is Michla and her father is Daniel.
Milton came back to me with this link. https://en.wikipedia.
The entry begins
Daniel Mendoza (5 July 1764 – 3 September 1836) (often known as Dan Mendoza) was an English prize fighter in the 1780s and 90s, and was also an instructor of pugilism. He was of Sephardic or Portuguese Jewish descent
The Wikipedia entry goes to great length about Mendoza's career, his Jewish background and his contributions (including two books) to the sport of prizefighting.
There does not appear to be a list of Daniel Mendoza's children, but Wikipedia says that he married his first cousin and they had eleven children.
Milton believes that Matilda's father Daniel is Daniel Mendoza the prizefighter. Who am I to disagree?
