Even though it is an extremly good work of fiction most of the history isn't true. The supposed history of the Priory of Sion is more or less a hoax; most historians willl tell you that there is little evidence it was even a thousand years old.
still a good book
After I had finished reading "The Da Vinci Code" and felt smart knowing everthing dan brown wrote, i went to wikipedia to learn more about the priory of sion; turns out it was just a little supported theory.
The book that suddenly makes everyone an expert on religion. A realization must be made that the Da Vinci Code is based on things we possibly know, but aren't sure, but quite probably could be true but not really.
Apparently by reading the Da Vinci Code in 2 weeks or so, I know more than historians who have been studying religion for years.