Of the Bishops of the Large Towns in the Reign of Constantine; and how, from fear of Licinius, Christianity was professed cautiously in the East as far as Libya, while in the West, through the Favor of Constantine, it was professed with Freedom
During the consulate of Constantine Cæsar and Crispus Cæsar, Silvester governed the Church of Rome; Alexander, that of Alexandria; and Macarius, that of Jerusalem. Not one, since Romanus, had been appointed over the Church of Antioch on the Orontes; for the persecution it appears, had prevented the ceremony of ordination from taking place. The bishops assembled at Nicæa not long after were, however, so sensible of the purity of the life and doctrines of Eustathius, that they adjudged him worthy to fill the apostolic see; although he was then bishop of the neighboring Berœa, they translated him to Antioch.
The Christians of the East, as far as Libya on the borders of Egypt, did not dare to meet openly as a church; for Licinius had withdrawn his favor from them; but the Christians of the West, the Greeks, the Macedonians, and the Illyrians, met for worship in safety through the protection of Constantine, who was then at the head of the Roman Empire.
Source: Ecclesiastical History (New Advent)