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. With these views, Diocletian had selected and embellished the residence of Nicomedia: but the memory of Diocletian was justly abhorred by the protector of the Church; and Constantine was not insensible to the ambition of founding a city which might perpetuate the glory of his own name. During the late operations of the war against Licinius, he had sufficient opportunity to contemplate, both as a soldier and as a statesman, the incomparable position of Byzantium, and to observe how strongly it was guarded by nature against a hostile attack, while it was accessible on every side to the benefits of commercial intercourse. Many ages before Constantine, one of the most judicious historians of antiquity had described the advantages of a situation, from whence a feeble colony of Greeks derived the command of the sea and the honors of a flourishing and independent republic.[50] The harbor of Constantinople, which may be considered as an arm of the Bosporus, obtained, in a very remote period, the denomination of the "Golden Horn." The curve which it describes might be compared to the horn of a stag, or as it should seem, with more propriety, to that of an ox. The epithet of _golden_ was expressive of the riches which every wind wafted from the most distant countries into the secure and capacious port of Constantinople. The river Lycus, formed by the conflux of two little streams, pours into the harbor a perpetual supply of fresh water, which serves to cleanse the bottom and to invite the periodical shoals of fish to seek their retreat in that convenient recess. As the vicissitudes of tides are scarcely felt in those seas, the constant depth of the harbor allows goods to be landed on the quays without the assistance of boats; and it has been observed that in many places the largest vessels may rest their prows against the houses, while their sterns are floating in the water. From the mouth of the Lycus to that of the harbor, this arm of the Bosporus is more than seven miles in length. The entrance is about five hundred yards broad, and a strong chain could be occasionally thrown across it, to guard the port and city from the attack of a hostile navy.