I Don't know much about History

Susan Viilante relates her fight to have a community college seminar on the DaVinci Code to try to stick to historical facts, and runs into a brick wall...

(she reports that her local community college offers this course: Da Vinci Code Historical Seminar giving the class description)..

Did you find the historical events in the 2003 fictional best-seller interesting but too fantastic to believe? Actually, most of the background items cited in the book were tied to events purportedly recorded in history.

She then writes: What really made me pause however was this line: "The Priory of Sion actually existed since 1099, and Opus Dei frightfully exists right here in the U.S.A., today!"

The Priory of Sion — the even older alleged conspiracy to protect the alleged descendents of Jesus Christ — certainly did not exist since 1099 (or ever), being a 1960s fabrication of a convicted French swindler.

Wikipedia agrees:
Although it has been characterized as anything from the most influential secret society in Western history to a modern Rosicrucian-esque ludibrium, it is generally thought that the Priory of Sion is, in large part, a hoax. Certainly, there is no published and approved historical evidence that establishes its existence before 1956....