His horse is spooked and rears back, but constantine looks up. A radiance brightens his face, and he raises his hands in admiration. Perhaps he is praying.

We visualize the moment of Constantine's vision of the cross in the sky as just such a spectacular epiphany because we have already seen Bernini's luminous marble statue of the emperor astride his horse. During the mid-seventeenth century successive popes hired the gifted sculptor and artist Gian Lorenzo Bernini to complete the new Church of St. Peter in the Vatican. In addition to his grand decoration of the interior, Bernini designed semicircular colonnades to embrace the vast elliptical piazza in front of the church. He also added an oversize statue of Constantine, located in a niche at the juncture between the corridor from the north colonnade and the front portico of the church. In contrast to earlier equestrian statues that had commemorated the generic majesty of emperors, this statue portrayed a precise dramatic moment, “the very turning point of Constantine's life, an instant when the emperor was himself subjected to a superior power.” As a result, the installation of the statue in this church seemed to link Constantine's vision with the defense of Christianity and, more specifically, with the enhancement of the power of the popes.

Later historians and churchmen were keen to requisition and exploit the episode of Constantine's vision of the cross. Another episode with obvious potential for reassessment was his baptism.