In The DaVinci Code, the Senechaux and the Grand Master of the Priory of Sion are the men who are put in charge of keeping the Holy Grail safe. At the time of the novel, Jacques Sauniere, Sophie Neveu's grandfather, is the Grand Master, but he is murdered just before the book opens. As Langdon and Sophie try to solve his murder, they figure out the clues that reveal details about the Priory and the Senechaux. At one point in the novel, there is a list of all the past Grand Masters, and some famous historical names appear listed here. During the course of the book, it is unclear who will take over Jacques's role now that he is dead--the other men in his circle were also murdered.