According to another version Peter cured his daughter, but he greatly protected her virginity. Petronilla took vows of chastity and was so firm in them, that when the opportunity to marry arose, after three days of consideration, she received the sacrament, and dying entered heavenly glory. According to still another version, she was locked away in a tower and consumed with love for a pagan prince, whom she could not marry, she died. It was not until the IV century that she was given a name, which was a reference to the name of her father. In the V and VI centuries we still see her as the daughter of the apostle, however in the IX century his fatherhood takes on a spiritual dimension, while apocrypha present him as a patron and a supporter upholding Petronilla in her vows of chastity. In subsequent centuries Petronilla was gradually “disconnected” from St. Peter and identified with a martyr from the turn of the III and IV centuries. Perhaps any memory of her would have faded into obscurity, had it not been for the beautiful painting The Burial of St. Petronilla, which was painted by Guercino in her honor and which found itself in St. Peter’s Basilica (San Pietro in Vaticano). This location was not selected by accident. When the tomb of a woman named Petronilla was discovered in the Catacombs of Domitilla, her remains were transferred in the middle of the VIII century to the then-existing Mausoleum of St. Andrew, located next to the transept of the Vatican Basilica. Her relics were in a particular way revered by the King of Franks – Pepin the Short, who during his visit in Rome, funded a chapel dedicated to Petronilla. He perfectly understood, how to take advantage of the appropriate moment of the translation of the saint’s body. She became a symbol of the bond between Rome and the ruler of the Franks, which since that time had almost acquired a familial dimension: Peter symbolized Rome, his daughter Petronilla – the kingdom of the Franks (while in the future France). It is from here that the French conviction stems that their Church is the firstborn daughter of the entire Holy Roman Catholic Church. After the reconstruction of St. Peter’s Basilica in the XVI century, the saint’s relics were transferred to the right transept and the aforementioned altar was placed there as well. Guercino’s painting itself was in time placed in the Capitoline Museums (Musei Capitolini – Pinacoteca). A mosaic, which is a copy of the painting, created in 1730 is found in the altar.