The Holy Grail is well known to all people familiar with Christian culture. This image, symbolizing a certain lofty and unattainable goal, has now entered everyday speech and everyday symbolism; legends about it are rooted in modern life as firmly as in ancient times. And they continuously give rise to many interpretations and insinuations. Take, for example, Dan Brown's The Da Vinci Code. At the same time, the Grail does not carry any specific religious content and is not mentioned in the Bible. Until now, experts have not resolved the question of what this mysterious sacred object was - a cup with the blood of Jesus Christ, a sacred dish, or a casket in which the shroud with the imprint of the Savior’s body was kept? What actually lies behind this incomprehensible and inexplicable symbol? Dan Brown certainly will not answer these questions, but the closest to answering them is Richard Barber, a famous researcher of medieval history and literature, director of one of the leading publishers in the field of medieval studies, Boydell & Brewer". In his large-scale work, he processed and compared a huge amount of information - everything that modern science knows about the Holy Grail. The variety of ideas and hypotheses reflected in this book illustrates the striking influence of the image of the Grail on the culture of Christian Europe, occult and mystical movements, ideology and sacred mythology of secret religious societies from the Middle Ages to the present day.