The distinction between
descendant and
agnatic descendant is often ignored. Essentially every European is descended from Charlemagne — usually in millions of different ways, but does he have any living
agnatic descendants? If my mother's father's mother's mother's father's mother's ... father was Charlemagne then I am his descendant, but to be his agnatic descendant (and thereby eligible to inherit his titles under Salic law) he must be my father's father's father's father's father's ... father — no female links allowed. In that case I would have inherited my Y-chromosome from this famous Emperor of the West.
So: Does this famous Emperor have any
living agnatic descendants? Apparently not. The Counts of Ulster may have claimed agnatic descent from Charlemagne, but their agnatic line went extinct centuries ago. The last person certain to have had the Carolingian Y-chromosome was
Odo I, Count of Vermandois. His
very brief Wiki article reveals the key details. He was heir to Vermandois but was disinherited because of some mental disability. Vermandois went to his sister's husband, Hugh the Great of the House of Capet, Leader of the First Crusade. As a consolation prize, Odo "the Insane" became "Comte de Saint-Simon" in 1085.
Odo then disappears from historical records.
Do the subsequent Rouvroy Counts of Saint-Simon descend from Odo? Nobody knows. AFAIK there are no plans to disinter any of the Carolingian kings for a DNA sample. But as a hobbyist with a vague interest in ancient genealogies I was intrigued to learn of an important 19th century thinker from the Rouvroy-Saint-Simon family.
These days, Internet genealogies are dominated by giant pedigrees at sites like Geni.Com. Clicking there just now, I see that they have a pedigree for the famous thinker Politesse mentions. And that pedigree shows an
agnatic ancestry that traces all the way back to ...
Charlemagne, King of All Franks and Emperor of the West!
(No complaints please: I did put this in Hide tags.)