OK so I don't know what they fuck you're talking about. But how do you KNOW Charlemagne is a descendant of Christ? Do you have DNA? How do you even know who Christ was? How do you know he was Divine?
He doesn't. And if he's based his belief system on those books, he's got himself 100% dead wrong, because in them Charlemagne wasn't a descendant of Christ, but one of the villains of of the piece, a usurper whose family with the connivance of the Catholic Church and the Papacy forswore their allegiance to Christ and his descendants and supplanted him/them.
As the story goes, Christ survived the crucifixion and/or was married with children. At some time subsequent to the faked death on the cross, either Christ himself and/or his descendants carting along his corpse wandered themselves north of the Alps and east of the Rhine and there, as Jews, established themselves as Kings of one of the tribes of Franks, a Germanic people who later invaded and settled in that part of the Roman Empire which is now France, where they established themselves as kings.
The genealogy of this royal family is complex and convoluted ... not to mention confusing. At one point, we have a woman, the foremother of the race who had a single son from whom all further were to descend. This woman, from such records as there are, appears to have been simultaneously married to two different men. As if bigamy wasn't enough complication for the poor woman to handle, one morning while she was frolicking on the beach, a sea-monster rose up from out of the deep -- an obese, hulking, horned creature -- and raped her ... one of those
I am the walrus goo goo g'joob vicissitudes to which ancient familes sometimes were prone. Thereafter, no-one was entirely sure to whom to ascribe the paternity of her son, whether to one or the other of her husbands or to [STRIKE]Paul[/STRIKE] [STRIKE]the walrus[/STRIKE] the creature from the black lagoon.
Skipping ahead, if madness hasn't already taken its toll, a vast conspiracy has taken place over the ages to suppress knowledge of these descendants of Jesus. Amongst those involved in one way or another, on one side or another, are the Roman Catholic Church, all Popes since around the year 800 or so, Leonardo da Vinci, the Knights Templar, Nicolas Poussin, Nicolas Fouquet, the Man in the Iron Mask, Napoleon Bonaparte, Heinrich Himmler ... and on and on it goes.
The whole thing is a crock. It's a hoax perpetrated in the 1950s/1960s by a self-admitted fraud and shyster to prove that he was the future king foretold by Nostradamus. He forged a bunch of documents purporting to link up a number of historical strings, and then smuggled them into a library archive and planted them there. Then he spent some time pointing others in their direction, amongst them a writer -- by turns an ultra-Catholic, Trotskyist, surrealist, friend to Tito, and so on and so forth, until he decided to give all that up and become a farmer. Then he decided he would become a writer on fringe subjects. His own son freely admits that all the so-called documents are forgeries, and that all of his books are (I quote) "absolute piffle".
These
productions were later found by a group of Brits, who used them to produce a series of books ... from which our friend Voltron, taking them as gospel truth, has derived his belief system. Dan Brown was later to use them as "sources" upon which to base his book.
The whole thing is a hoax, based on forgery and fraud.
Develope a vaccine (Salk), invent a illumination device (Edison), design & build a significant building (Wright's Falling Water or Gugeiheim Museum), build a machine to break an unbreakable code (Turing), walk on the Moon (Armstrong) or be a bumbling idiot (Trump or Groucho or Red Skelton 
)
