In 390 A.D., the Emperor Theodosius — the same Emperor Theodosius who had made Christianity the state religion of Rome — ordered a massacre in the city of Thessalonica, some of whose citizens had revolted. Seven thousand people died, many of whom had played no part in the uprising. When Theodosius subsequently appeared in Milan and attempted to attend Mass, Ambrose, the city’s bishop, physically stopped him from entering the church. According to a roughly contemporaneous account by a church source:
When Ambrose heard of this deplorable catastrophe, he went out to meet the Emperor, who—on his return to Milan—desired as usual to enter the holy church, but Ambrose prohibited his entrance, saying “You do not reflect, it seems, O Emperor, on the guilt you have incurred by that great massacre; but now that your fury is appeased, do you not perceive the enormity of your crime? You must not be dazzled by the splendor of the purple you wear, and be led to forget the weakness of the body which it clothes. Your subjects, O Emperor, are of the same nature as yourself, and not only so, but are likewise your fellow servants; for there is one Lord and Ruler of all, and He is the maker of all creatures, whether princes or people. How would you look upon the temple of the one Lord of all? How could you lift up in prayer hands steeped in the blood of so unjust a massacre? Depart then, and do not by a second crime add to the guilt of the first.
Theodosius, the account continues, “who knew well the distinction between the ecclesiastical and the temporal power,” submitted to the rebuke and repented. At Ambrose’s insistence, he decreed that a death sentence would not again be executed until 30 days had passed, so that the authorities could justly determine the facts. Ambrose then readmitted the Emperor to the church, but ordered him to remain with the laity outside the altar rail: “A purple robe makes Emperors, but not priests.”
Struggles between the Church and the Empire did not end in the fourth century, of course; indeed, they were just beginning. And this account does sound a bit tendentious. I imagine the Emperor (who, like Ambrose, is a saint, at least in the Orthodox tradition) had his own version of the story. But church-autonomy supporters have long argued that this episode shows that a distinction between church and state as institutions goes back to the very beginnings of Christian civilization in the West. And there it is, hanging in the Met. You see? Church and state issues really are everywhere.