The motives, whether of pride or of policy, which first induced Diocletian to withdraw himself from the ancient seat of government, had acquired additional weight by the example of his successors, and the habits of forty years.

Rome was insensibly confounded with the dependent kingdoms which had once acknowledged her supremacy; and the country of the Caesars was viewed with cold indifference by a martial prince, born in the neighborhood of the Danube, educated in the courts and armies of Asia, and invested with the purple by the legions of Britain.

The Italians, who had received Constantine as their deliverer, submissively obeyed the edicts which he sometimes condescended to address to the senate and people of Rome; but they were seldom honored with the presence of their new sovereign.
During the vigor of his age, Constantine, according to the various exigencies of peace and war, moved with slow dignity, or with active diligence, along the frontiers of his extensive dominions; and was always prepared to take the field either against a foreign or a domestic enemy.

But as he gradually reached the summit of prosperity and the decline of life, he began to meditate the design of fixing in a more permanent station the strength as well as majesty of the throne.

In the choice of an advantageous situation, he preferred the confines of Europe and Asia; to curb with a powerful arm the barbarians who dwelt between the Danube and the Tanais; to watch with an eye of jealousy the conduct of the Persian monarch, who indignantly supported the yoke of an ignominious treaty.