“These are the men, through whom the light of Christ’s gospel shone on thee, O Rome, and…”

These are the men, through whom the light of Christ’s gospel shone on thee, O Rome, and through whom thou, who wast the teacher of error, wast made the disciple of Truth.

Leo I · The Letters and Sermons · NPNF2 XII, Sermon LXXXII

On the feast of Peter and Paul, addressed to the city itself. It is the clearest statement of how Christian Rome understood its own succession from pagan Rome — not continuity but conversion — and Leo presses it by setting the two apostles against Romulus, who gave the city its name and defiled it with his brother’s blood.