The Synod of Antioch in Encaeniis (341 AD)

If any presbyter or deacon deposed by his own bishop, or any bishop deposed by a synod, shall dare to trouble the ears of the Emperor, when it is his duty to submit his case to a greater synod of bishops, and to refer to more bishops the things which he thinks right, and to abide by the examination and decision made by them; if, despising these, he shall trouble the Emperor, he shall be entitled to no pardon, neither shall he have an opportunity of defence, nor any hope of future restoration.

Ancient Epitome of Canon XII.

One deposed, if he shall have troubled the Emperor, shall seek the greater synod, and submit to its decree. But if he again misbehave himself, he shall not have any chance of restoration.

It is usually supposed that this canon, as well as the fourth, and the fourteenth and fifteenth, was directed against St. Athanasius, and it was used against St. Chrysostom by his enemies. Vide Socrates, Ecclesiastical History, Book II., Chapter viij., and Sozomen’s Ecclesiastical History, Book III., chapter v.; also ibid. Book VII., chapter xx.

This canon is found in the Corpus Juris Canonici, Gratian’s Decretum, Pars II., Causa XXI., Quæst. V., Can. ij., in Isidore’s Version.