capitals. For a time under Diocletian, Durazzo was the imperial capital. Ravenna, near the head of the Adriatic, was the capital of the last Roman emperors in the time of Alaric and Stilicho.

It was Constantine the Great who determined upon the permanent transfer of the centre of imperial power to the Bosphorus. We have already noted the existence of the city of Byzantium, which Constantine chose to develop into his new capital. It played a part in the story of the intricate Histiæus (chap. xxii, § 4); it repulsed Philip of Macedon (chap. xxiv, § 3). If the reader will examine its position, he will see that in the hands of a line of capable emperors, and as the centre of a people with some solidarity and spirit and seacraft (neither of which things were vouchsafed to it), it was extraordinarily well placed. Its galleys could have penetrated up the rivers to the heart of Russia and outflanked every barbarian advance. It commanded practicable trade routes to the east, and it was within a reasonable striking distance of Mesopotamia, Egypt, Greece, and all the more prosperous and civilized regions of the world at that period. And