In this publication, we present to the domestic reader the first translation into literary Russian of the first work dedicated to the Holy Grail, which was written by the French crusader knight (participant of the Fourth Crusade) Robert de Boron at the end of the 13th century. The novel is small in volume, so no less, it covers a vast time period and describes events that are important both for the further development of the novel in prose and for identifying the author’s ideas. The book is clearly divided into three unequal parts. The first, based on brief mentions in the canonical Gospels and on a more detailed story from the apocryphal “Gospel of Nicodemus,” tells about the passion of the Lord, about the feat of Joseph of Arimathea, about his captivity and rescue from prison. There was also room here for a brief story about the fall of Adam, about the biblical patriarchs, about the earthly life of Jesus Christ, the betrayal of Judas, Golgotha, the descent of Christ into hell, etc. In the novel, one can note a small but ideologically significant fragment that describes the first appearance of the Holy Grail, appearing in all its splendor and wondrous power. Both the power of the holy cup and the grace associated with it are revealed to Joseph. The second part tells about the liberation of Joseph, the conquest and destruction of Jerusalem by the troops of Emperor Vespasian, and the cure of the emperor from leprosy. Freed by Vespasian, who avenged the death of Christ, Joseph goes to distant unknown lands to preach Christianity there. The descendants of Joseph (this biblical character, according to church legend, could not have direct descendants, so Robert invented his nephew Lyonne) end up in England, where the brotherhood of the Grail is formed. For Robert, the brotherhood of the guardians of the Grail is a community of those involved in the sacred secret. Even the most chosen ones are not allowed to penetrate the mystery of the Grail. Joseph reveals this secret only to the future keeper of the shrine. The knightly novel about the search for the Grail was a trilogy. The first of them is “The Romance of the Grail” (this work also has another name - “The Romance of Joseph of Arimathea”). The other two parts of Robert's trilogy have not survived. From the second novel, “Merlin,” only the first 502 verses survived, from the third, “Perceval,” not a line. But the books of Robert de Boron were so popular in their time that we have, in a large number of lists, prose transcriptions of these works, which allows us to some extent judge the general intention of the novelist.