The Grail, a word well known to many for a long time, is a symbol of the eternal search for an incomprehensible goal, which the knights of King Arthur’s Round Table were tirelessly engaged in. Since the Middle Ages, the Grail has been surrounded by a veil of secrecy: none of the authors could really explain what exactly it is Is the Grail a tray, a cup or a vessel, and what exactly does it contain - the blood of Christ or the blood of ancient barbarian kings? Until the 20th century, the answer to this question was never found: writer Jules Berne, composer Wagner, and director Steven Spielberg in the film Indiana Jones and the Crusade offered their own version. Secret societies, such as the Bavarian Illuminati and the Thule Society, also dealt with the mystery surrounding the Grail. The Grail occupied a key place in the Nazi ideology of the Third Reich - for the SS chief Heinrich Himmler, it seemed to be a source of absolute energy, a symbol of ancient German traditions. The author of this book, the famous French researcher Jean Marcal, traces the entire path of the Grail through the centuries, showing how it changed and was often distorted ideas about the Grail and how it influenced the major events of world history. And the riddle of Rennes-le-Chateau, which still allows for various interpretations, invariably connects the search for the Grail with the name of Mary Magdalene.