What is the Priory of Sion? What's the Connection to the Holy Grail?

Also known as the Prieure de Sion or the Priory of Zion, the Priory of Sion is commonly used in works of fiction as a powerful, secretive organization that has been behind important events throughout Western history. Even some works purporting to be factual have included this claim and Dan Browns The Da Vinci Code blends both: a work of fiction claiming to be based on historical fact, incorporating the claim that the Priory of Sion has been behind such things as the Knights Templar. Read Article: What is the Priory of Sion? What's the Connection to the Holy Grail?