Since genealogy seems to be my hobby of the season, here’s a brief blog article that is worth reading:

You Are Probably Descended from Charlemagne and Other Royalty

The commenters seem a bit confused about things genetic, but that is common.

If your ancestors come from a European nation that kept good records, such as with my Norwegian ancestry, chances are indeed good you can find a way back to the great Kings of old. In my case it’s not too difficult to hit Scandinavian nobility of the 13th-15th centuries, in part because of all the baptismal and land ownership records the Norwegians kept, so I’ve got about a dozen entry points into the ancient past. The landed gentry/nobility tended to marry equally or “up”, so it takes several generations to lose the trail, and if you can follow your ancestry back to the 15th century in Europe the paths get easier.

Once you hit a landed gentry then the rest going back to Charlemagne (or another famous person) is pretty straightforward.

Note that going back before the Carolingian dynasty is rather questionable. For Scandanavian ancestors going before King Gorm is doubtful. In England the House of Wessex is real but descent from them is confusing.

There are many myths that the doubtful/fake genealogy research sites try to sell to people. For example, many people of Scandinavian ancestry try to claim a certain “Princess Hildis of the Vandals”, but she’s a myth. The myth is made so that one can claim her real (and important) father, Hilderic of the Vandals, as an ancestor. Hilderic is indeed important, and if you can find him in your tree, then that means you can find his ancestors, which include the Emperors of Rome, such as Constantine.

So everyone wants to claim “Hildis” - but as near as serious genealogists can tell she was invented by later people of the North, to insert into ancient proto-Viking ancestry.

Similarly, some who find the House of Wessex in their heritage buy the deception that Alfred, King of the Britons, was descended from Joseph of Arimathea. But that most certainly is a made up claim (even if there was a real Joseph of Arimathea as portrayed in the Gospels, which is itself unlikely.)

So, it’s buyer-be-ware out there.