FACT: The Priory of Sion - a European secret society founded in 1099 - is a real organization. In 1975 Paris's Bibliothque Nationale discovered parchments known as Les Dossiers Secrets, identifying numerous members of the Priory of Sion, including Sir Isaac Newton, Botticelli, Victor Hugo, and Leonardo da Vinci.

The Da Vinci Code (ed. Doubleday Books, 2004)