After the Council of Nicæa, a.d. 325, the faith of the Catholic Church was established, but a considerable time was to elapse, and the tide of heterodoxy was to ebb and flow many times before peace should finally ensue. The “conversion” of the Emperor Constantine, though not followed, till he was dying, by baptism, led not merely to the toleration but to the protection and, as it were, the “establishment” of the Christian religion. This very naturally was followed by a large influx of worldliness into the Church, and bishops began to be time-servers and courtiers. St. Ambrose, however, was not of this number, but whether in defence of the Catholic faith, of the property of the Church, or, as in his legations to Maximus, for the protection of those in peril or anxiety who sought his aid, he braved every danger, even that of death itself.