In the first place, the political relation of the city of Rome to the Roman world had undergone a fundamental change. The citizens of that wonderful city were no longer the proprietors and sovereigns of the realm over which the Roman eagles had spread their wings. The Senate which assembled in the Curia, the people which gathered in the Forum Romanum, had ceased to rule subject cities and nations. That glory had departed. In Gibbon’s mordant language, “The Senate was left a venerable but useless monument of antiquity upon the Capitoline hill.” Every freeman within the Empire’s bounds was now the equal of the men whose forefathers had been the kings of the world. Rome was now only one of the great cities of the Roman State, differing from her peers only in the memories and the prestige of a happier and grander past. The government of the world by the city had broken down, and was vested in the hands of one supreme man. And that man had gradually become an absolute lord and monarch; who exercised plenary authority wherever he chose to reside, who decked himself with jewels and resplendent robes, who made his throne the lofty peak of a vast hierarchy of nobles and officials, and introduced new methods of administration; a man, perhaps, without a drop of the blood which Romans proudly bore, but a rude provincial, yet to whose will the Eternal City bowed as humbly as the remotest village beneath his sceptre. If a Cassius still lived he might, pointing to the Master of the Empire, well exclaim, “He doth bestride the narrow world like a Colossus, and we petty men walk under his huge legs, and peep about to find ourselves dishonourable graves.... Rome, thou hast lost the breed of noble bloods!” That a city which had been sovereign and self-centred should remain the head and representative of a cosmopolitan State, and of an autocratic Government, was something incongruous and unnatural.
Nor was this the only respect in which the old order had changed and given place to new. Under Constantine the attitude of the Roman Government towards the Christian Church was the direct opposite of that maintained by his predecessors. What they had regarded as a hostile organisation, he welcomed as an ally and friend. What they had endeavoured to uproot and destroy, he cultivated and supported. That he entertained a sincere respect for Christianity as a moral and social force, and believed that there was something Divine associated with it, cannot be doubted. And in his opinion, it was the part of true statesmanship to accept the religious and moral revolution that had come into the world, and to utilise it for the welfare of the Empire. This is not the place to discuss the question how wisely the alliance between Church and State was effected, or to decide how much the parties to the union thereby gained or lost. It is enough for our purpose to recognise that the union introduced as profound a change of policy as can be introduced into the affairs of men, that it widened the breach between the past and the present, and rendered the embodiment of the new system of things in forms peculiar to itself perfectly natural, if not inevitable. This was the more certain to occur, seeing Rome continued to be the centre of opposition to the new faith.