""(1) [Constantine] also passed a law to the effect that no Christian should remain in servitude to a Jewish master, on the ground that it could not be right that those whom the Saviour had ransomed should be subjected to the yoke of slavery by a people who had slain the prophets and the Lord himself. If any were found hereafter in these circumstances, the slave was to be set at liberty, and the master punished by a fine. (2) He likewise added the sanction of his authority to the decisions of bishops passed at their synods, and forbade the provincial governors to annul any of their decrees: for he rated the priests of God at a higher value than any judge whatever." [Eusebius, L.C., Book IV, Chapter XXVII]"
Eusebius, L.C., Book IV, Chapter XXVII