I first read this book as a teenager and thought it was the coolest thing ever, but after re-reading it as an adult ... it really didn’t age well.
While re-reading it, I had my first good laugh when Baigent, Leigh, and Lincoln 1) attribute Godefroy de Bouillon selling most of his property before setting out on the First Crusade to him knowing beforehand that he’d be made king of Jerusalem from the beginning and 2) state that he was the only one to do this. Simply researching the First Crusaders would show that all of the would-be Crusaders had to sell or mortgage their lands and castles before setting out, even much wealthier nobles like Raymond IV of Toulouse, Hugues de Vermandois, and Robert Curthose of Normandy. This is because aristocrats of the time were rich in land, not currency, so mortgaging their property and taking out loans before pilgrimages or war was a given. The authors also posit a close relationship between Godefroy de Bouillon and Matilde of Tuscany, his maternal uncle’s wife, when the historical record is pretty clear that the two of them hated each other, due to inheritance disputes that had arisen when said uncle (Godefroy III of Lower Lorraine) was assassinated in 1076.
Their handling of history from the Early Middle Ages is no better. In a section about Dagobert II, they attribute a section about Gregory of Tours’ History of the Franks as a criticism of Dagobert when the actual target was Chilperic I of Neustria, an earlier Merovingian king. Somehow, Baigent, Leigh, and Lincoln failed to notice that Gregory of Tours couldn’t have been talking about Dagobert II in that section because Gregory died around 50 years before Dagobert’s birth. The authors also do not seem to be aware that virtually everyone from the Romans onward claimed Trojan ancestry (because they, rather understandably, found Hector and the Trojans in the Iliad more sympathetic than Agamemnon and the Mycenaeans), that counthood was not hereditary during the early Carolingian era, or that the Visigoth kings of Spain did not have hereditary kingship.
Central to Baigent, Leigh, and Lincoln’s theory is established mostly on the basis that medieval romances claimed that Godefroy de Bouillon’s grandfather was Lohengrin the Swan Knight, son of Percival. Regardless of the fact that medieval romances should not be taken as historical fact (historically, Godefroy de Bouillon’s actual grandfathers were Eustache I of Boulogne and Godefroid II of Lower Lorraine), Naissance du Chevalier au Cygne actually names Godefroi’s maternal grandfather as Helias the Swan Knight, son of Orient de l’Islefort. This is because the legend of the Swan Knight was originally a separate story that was later folded into Arthurian legends by Wolfram von Eschenbach. It was Wolfram who gave the Swan Knight the name Lohengrin and made him the son of Percival. Despite their attachment to the myth of Ide of Lorraine’s descent from the Swan Knight, they mostly posit that instead that her husband, Eustache II of Boulogne, was the descendant of Dagobert II and thus, of Jesus as well. This makes their sudden shift to interest in the House of Lorraine all the stranger, because Eustache was only connected to the Duchy of Lorraine through his marriage to Ide. One of his sons, Godefroy, eventually succeeded to the Duchy, but he fathered no children so his claims died with him. Godefroy’s older brother, Eustache III, did have a daughter, Mathilde, but none of Mathilde of Boulogne’s descendants made any claims to the duchy of Lorraine and they only intermarried once with the House of Metz, on account of Mathilde’s granddaughter, Marie I of Boulogne, being abducted by and forcibly married to Mathieu of Alsace, a paternal grandson of Thierry II of Lorraine. Later on, Mathilde’s great-granddaughter, Adelheid of Brabant, married the count of Auvergne and her descendants include Caterina de’ Medici and the viscounts of Turenne. The authors’ second-rate research, however, means that they don’t seem aware that the viscounts of Turenne (who they attempt to bring into their conspiracy) were in fact descendants of Godefroy de Bouillon’s older brother. I know genealogical research wasn’t as easy in the 1980s as it is today, but come on.
Returning to the subject of Eustache I of Boulogne, however, the authors’ make the laughable claim of him being the son of someone named Hugues de Plantard, he was actually the son of Baudouin II of Boulogne and a descendant of Baudouin Iron Arm of Flanders and the Carolingian princess, Judith of France. The Ernicule of Boulogne they misidentify as Eustache I of Boulogne’s stepfather is probably a garbled translation on their part of Enguerrand I of Ponthieu who married Eustache’s mother, Adelina of Holland, after killing his father in battle. For some reason, though, the family tree in this book further misidentifies Eustache’s mother as Agnes and claims she was the daughter of Eustache, count of Jumièges, a baffling error because there was no such title as “count of Jumièges”; Jumièges was instead the property of a Benedictine Abbey that was later destroyed during the French Revolution. Said family tree also accidentally omits that Saint Ide of Lorraine was the niece of Pope Stephen IX and daughter of Godefroy the Bearded of Lorraine and that Godefroy the Bearded’s second wife, Beatrice of Bar, was also his third cousin and gives Godefroy and Pope Stephen a fictitious sister named Beatrice who married Hugues de Plantard. In reality, Stephen and Godefroy did have three sisters (Regelinde, Ode and Mathilde), but none was named Beatrice.
Upon reaching the Late Middle Ages, Baigent, Leigh, and Lincoln try to posit that Rene d’Anjou alone was the cause of the Renaissance with nary a mention of Petrarch, Coluccio Salutati, or Manuel Chrysoloras, either because the authors don’t know of them or to make their flimsy thesis seem stronger than it actually is. I had another good laugh, though, when the authors mistakenly conflated Henri de la Tour d’Auvergne, duc de Bouillon, with his youngest son, Henri de la Tour d’Auvergne, vicomte de Turenne, and then try to hint about a family link between the two Henris and Godefroy de Bouillon because the elder Henri held the title duc de Bouillon. In reality, how Henri de la Tour d’Auvergne came about that title is no mystery: he married Charlotte de La Marck, duchess of Bouillon. Charlotte’s family came about the title after Henri II of France officially bestowed it on her grandfather, Robert IV de La Marck, though the de La Marck family had first claimed lordship of Bouillon after Guillaume de La Marck assassinated Louis de Bourbon, Bishop of Liège (previous holder of the title) in 1482. That noble families might go extinct and titles be bestowed on unrelated families is a concept foreign to the authors, which is probably why they try to conflate the House of Ardennes-Verdun with the House of Metz simply because both held the title duke of Lorraine. It is indeed possible that the two were related (the wife of the founder of the House of Metz may have been one of the daughters of Thierry I, Duke of Upper Lorraine), but the authors don't seem aware at all that the House of Ardennes-Verdun became extinct in 1076 with the assassination of Godefroy III of Lower Lorraine. This, however, is probably due to the shoddy genealogical research that I complained of earlier.
In terms of religious content, Baigent, Leigh, and Lincoln have trouble understanding the difference between Gnosticism and Arianism and don’t really understand the religious doctrines of either. They claim that Arianism is the belief that Jesus Christ was mortal when it’s actually the belief that God the Son was created after God the Father, and seem to think that Gnosticism was the same thing as believing that Jesus Christ was a mortal prophet. In reality, the Gnostics posited Jesus Christ as entirely divine and that his mortal form was nothing more than an illusion. This is because the Gnostics generally seem to believed that the material matter was a creation of an evil (or at least flawed) demiurge and that Jesus was sent by the true God to free mortals from the material world. This why the Gnostics claimed that Jesus wasn’t really crucified, but Baigent, Leigh, and Lincoln either don’t understand this or they ignore it because it doesn’t fit with their thesis. Likewise, they're positing of the Cathars' being guardians of the secret of Jesus' bloodline makes little sense because the idea of Jesus fathering children would have been far more offensive to Cathar beliefs than Catholic ones. This is because, like the Gnostics, the Cathars also believed that Jesus had never actually taken human form and furthermore, their view of sex and marriage was so negative that it made Catholic theologians of the time look like advocates of free love by comparison. Bizarrely, the authors’ do comment on the Cathars’ disapproval of reproduction, but then fail to note how that doesn’t lend itself well to the notion of them guarding the secret of Jesus fathering children. Either they didn’t think this one through or they threw it the Cathars to make their insubstantial theories seem stronger than they actually are, because they happened to be from around the same general geographical location as Rennes-le-Château.
Overall, "Holy Blood, Holy Grail" is a muddled mess . Upon re-reading it, I noticed Baigent, Leigh, and Lincoln can’t seem to make up their minds if the Grail bloodline flowed from Eustache II of Boulogne or Ide of Lorraine, so they attempt to do both at once and it makes about as much sense as you’d expect. They jump around from Godefroy de Bouillon to the Cathars to the Knights Templar to René d’Anjou and Jeanne d’Arc to the Guises and the Stewarts to the Rosicrucians without fully explaining what the continuity between these things is supposed to be. This is probably because the Priory documents forged by Pierre Plantard and Gérard de Sède themselves don’t make a lot of sense, either. When coming up with leaders of their fictitious organization, Plantard and Sède simply picked names that sounded impressive rather than ones that had any kind of religious and philosophical continuity. Ironically, the conspiracy theory the authors’ posit could have made slightly more sense if they’d done more research. If, for instance, they had actually researched the family trees of the Counts of Boulogne and Dukes of Lorraine, they might have noticed that the Chrétien de Troyes’ romance about the Holy Grail was dedicated to Philippe I, count of Flanders, who was related to the counts of Boulogne, dukes of Lorraine, and counts of Anjou. Now, I’m not saying this would be a great conspiracy theory, much less a true one, but it would make slightly more sense.