with the senior Augustus. In this way three advantages were gained: the vast work of government was subdivided; the unity of empire was preserved; and the succession was regulated, in a peaceful and orderly method. Then, by settling his court at Nicomedia, Diocletian already began to transfer the centre of gravity in the empire from Rome to the East. Constantine came to the throne under this arrangement. His father was Constantius Chlorus, of a noble Dardanian family, who had been Cæsar over the provinces of Gaul, Spain, and Britain, and then Augustus. His mother was the famous Empress Helena, whose traditional "Invention of the Cross" has made her a conspicuous figure in Christian art. By a confusion of traditions she has been taken for a British princess of the same name; but she was really a Cilician and servant at an inn. Helena has been described as a "concubine" of Constantius; but she must not be regarded as only the emperor's mistress. There can be no doubt that they were husband and wife according to a secondary order of marriage recognised in the empire at the time.
The young Constantine was brought up at his mother's village home till he was sixteen years old, when the suspicious Diocletian had him come to reside at court in Nicomedia, evidently as a hostage for his father's good conduct. When Constantius became Augustus he sent for his son to help him with the government (a.d. 305). Though outwardly consenting, Galerius, who was senior Augustus at the time, was really unwilling to let him go, and Constantine had to slip away secretly and hurry Westwards to escape recapture. The next year (a.d. 306) Constantius died at York, having nominated his son as his successor; and at York Constantine was hailed by the soldiers as Augustus. When he had obtained supreme power, Constantine, like Diocletian, made the centre of his government in the East. For a time Nicomedia, not Rome, was the real capital of the empire. Then Constantine determined to found a new Rome. With the insight of genius he chose Byzantium as the site, and built there the
