All in the family
Let's take a look at one of those surprising facts from history. Be warned, it is obscure, unverifiable and possibly untrue -- so the word "fact" may be stretching it a bit. But I guess it'll do for a "fact" until the real thing comes along.
To set the scene for our little surprise, we need to go back in time to Spain in the age of the Reconquista. As you may know, much of the Iberian peninsula was conquered by Islam in the early middle ages -- and by 1492, the same year Columbus "sailed the ocean blue", the middle ages and the Moorish occupation of the peninsula were over. This era of reconquest of Spain and Portugal by Christian forces is called, borrowing the word from Spanish, the Reconquista.
In between the beginning of the Moorish establishment in Spain and the end, there was a long period of wars, accommodations and intermittent coexistence. Like the crusader kingdoms in the Levant, the Christian and Muslim rulers of Spain often found good political reasons to make alliances across the divide of religion.
One of these Christian monarchs was Alfonso VI of Leon and Castile (born before June 1040, dead July 1, 1109), the first king to style himself "king of all Spain", and one of the larger-than-life figures of El Cantar de Mio Cid, "The Lay of the Cid".
Alfonso had many wives. He was married at least five times, and the recorded parentage of his children is rather vague. Genealogies tend to mention the probable mother of a particular child from among his list of wives, and a number of alternate possibilities (this, by the way, is why I mentioned earlier that this story is unverifiable).
At any rate, let's focus on one of Alfonso's wives in particular. She has several names. In official genealogies, she appears as Isabella of Denia (born about 1071, died 1107).
Isabella is almost certainly the mother of Alfonso's only son, Sancho (who never attained the throne, having predeceased his father at the Battle of Ucles in 1108). She is also variously listed as the possible mother of Alfonso's other children Sancha and Elvira Alphonsez. They're both pretty interesting, so let's have a closer look at them.
Sancha married Rodrigo `El Franco' Gonzales de Lara, and counts among her descendants the Portuguese King Dionisio Henriques (1261-1325), whose descendants number every single Catholic royal family in Europe.
Nor did Elvira's blood line go into historical obscurity. No, not at all. Her first husband was Raymond IV, count of Toulouse, and her second was Roger II Guiscard of the Norman kingdom of Naples. From these marriages, Elvira had several children, including King William I `the Bad' of Naples and Sicily, and Roger III de Hauteville. From the latter gentleman, many if not all of the dynasties of the German kingdoms and princely states descend.
Oh, heck, let's cut to the chase: so far as I can reliably determine, an index of the descendants of Alfonso VI and Isabella would be a complete listing of every single European royal family, most of the nobility, and many of the prominent families of the élites of other nations (including the United States of America, which, like the late Roman republic, is more of an aristocracy than a republic).
Just for instance... Isabella's the 23 times great-grandmother of Queen Elizabeth II of the United Kingdom. Or, in another line of descent, the 24 times great-grandmother of Diana Spencer, the late Princess of Wales.
So why is that line of descent so interesting? Good question.
Well, Isabella wasn't born with that name. Actually, her name used to be Zaida. Nor was she a Christian, until she was forcibly converted to Catholicism. She was, in fact, the daughter of the deposed Emir of Sevilla, Abul-Kasim Muhammad ben Abbad al-Mu'tamid (born to wealth and power about 1040, died in poverty 1095).
Again, so what?
Well, the Emir of Sevilla wasn't just a nobody. In fact, he came from a pretty prominent lineage. More precisely, 16 generations before he came along, one of his ancestors had founded a new world religion.
That's right, Abul-Kasim Muhammad ben Abbad al-Mu'tamid was a lineal descendant of the Prophet Muhammad.
In other words, so is every single royal family in Europe.
That sort of puts an interesting perspective on the entire issue of Islamic marginalisation in Europe, doesn't it? It opens up all sorts of job opportunities for down-on-their luck European nobility and royalty. "Convert to Islam, and you'll be a candidate for Caliph..."
Facetious, I know, but interesting. Still, I promised you a curious fact, and I hope you'll agree that I've delivered, as promised.