Once there, they intermarried with the noble families that would eventually become the Merovingian dynasty, whose special claim to the throne of France is championed today by a secret society called the Priory of Sion.

"[9] In a 1982 review of the book for The Observer, novelist and literary critic Anthony Burgess wrote: "It is typical of my unregenerable soul that I can only see this as a marvellous theme for a novel.

Comparing themselves to the reporters who uncovered the Watergate scandal, the authors maintain that only through speculative "synthesis can one discern the underlying continuity, the unified and coherent fabric, which lies at the core of any historical problem."

According to the authors' claims, the Priory of Sion is devoted to restoring the Merovingian dynasty, which ruled the Franks from 457 to 751, on the thrones of France and the rest of Europe.

According to them, the legendary Holy Grail is simultaneously the womb of saint Mary Magdalene and the sacred royal bloodline she gave birth to, and the Church tried to kill off all remnants of this bloodline and their supposed guardians, the Cathars and the Templars, in order for popes to hold the episcopal throne through the apostolic succession without fear of it ever being usurped by an antipope from the hereditary succession of Mary Magdalene.

Per Baigent et al, the text was not intended to be released publicly, but was a program for gaining control of Freemasonry as part of a strategy to infiltrate and reorganise church and state according to esoteric Christian principles.

After a failed attempt to gain influence in the court of Tsar Nicholas II of Russia, Sergei Nilus was supposed to have changed the original text to forge an inflammatory tract in 1903 in order to discredit the esoteric clique around Papus by implying they were Judaeo-Masonic conspirators but ignored some esoteric Christian elements, which hence remained unchanged in the published antisemitic canard.

Infant mortality in pre-modern times was ridiculously high, and you'd only need one childhood accident or disease in 2000 years to wipe out the bloodline; if, however, even one extra sibling per generation survived to reproduce, the numbers of descendants would increase at an exponential rate; keep the children of Christ marrying each other, on the other hand, and eventually they'd be so inbred that the sons of God would have flippers for feet.

[9]In 2005, Tony Robinson narrated The Real Da Vinci Code, shown on Channel 4, a critical evaluation of the main arguments of Baigent, Leigh and Lincoln (and subsequently Dan Brown).

Despite the "Priory of Sion mysteries" having been exhaustively debunked by journalists and scholars as France's greatest 20th-century literary hoax,[22][23][24] some commentators express concern that the proliferation and popularity of pseudohistorical books, websites and films inspired by the Priory of Sion hoax contribute to the problem of unfounded conspiracy theories becoming mainstream;[25] while others are troubled by how these works romanticize the reactionary ideologies of the far right.

Alas, though, I think that one has to say that this is the direction that history is going today...[27]The 2003 conspiracy fiction novel The Da Vinci Code by Dan Brown makes reference to this book, also liberally using most of the above claims as key plot elements.

The claim was rejected by High Court Judge Peter Smith on April 6, 2006, who ruled that "their argument was vague and shifted course during the trial and was always based on a weak foundation."

Stewart Copeland, former drummer for the rock band The Police, composed the opera Holy Blood, Crescent Moon, heavily inspired by this book.