THE REAL HISTORY BEHIND THE DA VINCI CODE Millions have been enthralled by The Da Vinci Code's fascinating historical speculations-and the blockbuster novel's audience has also made bestsellers of several books offering to separate the facts from the fiction.   This comprehensive, encyclopedic volume is written by an acclaimed medievalist-and takes an objective, history-based approach to the phenomenon and the questions it has raised.       The Real History Behind the Da Vinci Code gives easy-to-find, clear answers about the people, places, and events that play roles in Dan Brown's tantalizing thriller in a lively, encyclopedic format-shedding new light on some of the deepest mysteries of the Dark Ages.