One of the most controversial claims made by Brown in The Da Vinci Code was the union of Jesus Christ and Mary Magdalene, and the bloodline that existed due to the same. Moreover, there is no historical evidence that The Knights Templar discovered the Grail and were annihilated due to the knowledge of the same (although that hasn't stopped the Holy Grail from being a MacGuffin in dozens of King Arthur movies). This poem presents the Grail as a mysterious, live-restoring cup, which is used as a reference point by Brown, who then alters the premise into claims about Jesus and Mary’s sacred bloodline. The first association between the Templar and the Holy Grail can be traced back to German writer Wolfram von Eschenbach, and his Arthurian epic poem, Parzival.
Historically, The Knight’s Templar or The Order of Solomon's Temple was a Catholic military order founded in 1119, which were closely tied with the Crusades, as they were protectors of Christian pilgrims. Per Dan Brown, the legendary Holy Grail is not the literal chalice used in The Last Supper, but in fact, Mary Magdalene, a secret protected by The Knights Templar ( featured in Assassin's Creed as the real-life order of knights). When trying to answer the question of is The Da Vinci Code true, it's best to start with what's accurate.
