Every person of European descent can claim to be a descendant of a Roman politician! Realistically speaking, all of them who had kids, but the best documented would be this guy, Flavius Afranius Syagrius who was consul in the late 300s CE. When I say best documented, understand that I mean our best bet, as needless to say, establishing records for that is REALLY REALLY REALLY hard. I digress though, Flavius is considered a very likely ancestor of Charlemagne for a traceable line of descent, which is part of a larger goal, known as "Descent from Antiquity", kind of the holy grail of genealogy, where researchers want to document a reputable, traceable line from someone living today all the way back to ancient times. The other candidate is this guy, Anastasius, who was also a consul in the 500s, and himself descended from Valentinian. I won't pretend to be super well versed in the whole thing, so you can read up more on DFA here.

"Cool!" you're saying (I hope), "but how does this mean that I am descended from him too!?" Well, math. This is a favorite topic of mine, so I've written about it before. I'll drop the whole post down bloew, but the basic gist of it is, that the number of ancestors you have grows exponentially every generation, and by the time you reach 800 CE, when ol'Grandpa Charley was alive, they would, in theory, number in the trillions. The fact that they actually - that is a wee bit higher than the world population at the time - don't is easily explained. Those people are doubled, tripled... whatever the word for fifty-thousand timed is... up in your family tree. Amazingly, some researchers believe that the most recent common ancestor for everyone in Europe lived only 600 years ago! And it is pretty much taken as fact that everyone of European descent is descended from Charlemagne. So anyways, here is the full post I did, it was mainly about QE II and William the Conqueror, but the same holds true even more so for Charley, who I mention at the end.

Most likely, every white European can, with reasonable confidence, claim descent from William the Conqueror, and at that, any given Norseman who had descendants. William lived in the 11th century, so lets use 1064 for our start date. In genealogy, traditional calculations of generations use 25 years per generation. 2014 - 1064 = 950 years. Divided by 25 equals 38 generations.

This is important for two reasons. 32 Generations is the point where the number of theoretical ancestors in the 32nd generation (2^32 or 4,294,967,296) is larger than the number of base pairs (in the 3 billion range) in the human genome. In other words, 32 generations is the point where descent is (theoretically) statistically meaningless, and your genetic makeup is just as related to your ancestor as it would be to any random person you aren't descended from and was alive at that time.

It is important for a second reason because 2^38 equals 274,877,906,944. Yes, that is 275 Billion. That is the number of theoretical descendants of the old Bastard, assuming 2 children per generation (and for the record, he had ten known issue, so I'm being conservative in my estimates). Obviously, there is a LOT of closed loops there to account for the fact this number is orders of magnitude above the total number of people who have ever lived.

Even if we assume something like 90 percent of the lines go into dead ends before reaching modern times (which most genealogists wouldn't support anyways, if anything, it is the opposite), that's still 27,500,000,000 living descendants right now, so many times over what the current world population is.

So what is my point here? It is that you don't need to go very far back before claiming anything special about your ancestry becomes meaningless. Anyone who is of European ancestry is almost certainly descended from Charlemagne for instance, and probably William I as well. In fact, you can find estimates that place the most recent common ancestor of Europeans as having lived only 600 years ago (possibly a bit optimistic).

Now math is not exactly my forte, but if I visualize it correctly, if the population of the world is ~7 billion, and the theoretical descendants that this guy has now is 274,877,906,944, that is 40 theoretical descendants who should exist for every person currently alive. So if every person now alive can claim descent from him, they should, in theory, be able to trace back through 40 different paths, right?

If 1/10th of the world population is descended from him, the average descendant would be able to do it through 400 different paths! Aside from just being an interesting exercise in how closely we are related, this also relates back to the 32 generation cut off point. Because there are so many "closed loops", as I think of them, it means that that cut off point potentially gets pushed back.

Also, going back only a few more generations, to Charlemagne, we are getting into numbers in the trillions by the way.

Now anyways, to get back onto the topic, yes, as the Queen is a direct descendant of William the Conqueror, himself a descendant of the Norse, she would have ancestry of the Norse too, but as I pointed out, there are two huge asterisks. First, it is so far back as to be nearly genetically meaningless, as I pointed out. The second, and more important factor, is that what separates the Queen from everyone else of European descent isn't that she descended from these royal figures and that most people didn't, but rather than because of her specific line of descent being notable, we have the records of it still, while most people simply lack the written proof.

*Also, obviously, I do not take infidelity or adoption into account here, and take paternity at face value. If William kept getting cuckolded, and none of his kids were actually his, obviously none of this still applies.

So there you go. Just replace "Norsemen" with "Roman senators" and it all works.

When it comes to traceable descent from antiquity, in western europe, geneaologies around Rome (where the oldest known Roman families were based) start breaking down around the late 6th century after the Gothic Wars, so that by the 7th, even though its likely many of the remaining elite of Rome were descended from Roman families of antiquity, the demise of the tria nomina system left no way for any lineage to be tracked.

This was also a mirror of what happened in the Byzantine Empire. Basically with the collapse of cursus honorum-like positions where the aristocracy was given preferential appointment and support by the state, there was no point in having an extended lineage during the chaotic time of the Arab conquest. In Byzantium, the system was by necessity meritocratic rather than purely nepotistic (we don't care who you are, if you can keep the invaders at bay, etc). After 2-3 generations, names reverted to simple single names followed by some kind of descriptor, rather than a formalized surname.

It was only later (I think 10th or 11th century in the west) and 9th century in the east that you see the reappearance of surnames that allow one to track descent, and this is only because the aristocratic power was on the rise.

tl;dr - Yes, Roman patrician families survived the fall of the western empire. No we can't say for certain who is a descendant of a Roman senator.