In this article, I examine the imperial and Christian elements of the legend of the Vision of Augustus and argue that the author of the Mirabilia manipulates the earlier versions of the Vision to create his own version. This version gives historical precedent to the papacy's twelfth-century attempts to establish its emerging, but still undefined, supremacy in both secular and ecclesiastical domains. Augustus kneeling before the baby Jesus vividly illustrates the subordination of imperial to ecclesiastical authority, just when the popes are struggling with western secular rulers and the revived Roman commune. At the same time, the papacy at Rome claims primacy over the other sees, especially Constantinople. In associating the imagery of the Marian feasts of the Hypapante-Purification and the presentation at the altar with the birth of Christ and the reign of Augustus in a vision located on the Capitoline Hill, the Roman papacy claims a primacy free of any historical or geopolitical bounds.