τὴν Καίσαρος τύχην. This oath was invented under Julius Cæsar, and continued under his successors. The oath was repudiated by the Christians, who regarded the “genius” of the emperor as a false God, and therefore the taking of the oath a species of idolatry. It was consequently employed very commonly by the magistrates as a test in times of persecution (cf. Tertullian, Apol. 32; Origen, Contra Cels. VIII. 65, and many other passages).