18 His apostolic energy led to his being unjustly deposed from his episcopal see, insulted by his brethren, condemned by an illegitimate council, and subjected to prison and many hardships; but he bore all with unruffled and invincible courage. And not only did he oppose the Bishops who had gone astray from the path of truth and unity; he did not hesitate, in the conscientious discharge of his holy duty, openly to resist even the Emperor himself. In addition to all this, as everybody knows, he wrote countless works in support and defense of the Christian faith, works which bear striking testimony to his extraordinary learning, his intrepid courage, and his pastoral zeal.
Source: Orientalis Ecclesiae (Vatican.va)