Thus, then, the Arians, with their affairs in a very flourishing condition, and everything turning out according to their wishes, go in a body to Constantinople where the emperor was. There they found the deputies from the Synod of Seleucia, and compel them by an exercise of the royal power to follow the example of the Westerns, and accept that heretical confession of faith. Numbers who refused were tortured with painful imprisonment and hunger, so that at length they yielded their conscience captive.
But many who resisted more courageously, being deprived of their bishoprics, were driven into exile, and others substituted in their place. Thus, the best priests being either terrified by threats, or driven into exile, all gave way before the unfaithfulness of a few. Hilarius was there at the time, having followed the deputies from Seleucia; and as no certain orders had been given regarding him, he was waiting on the will of the emperor to see whether perchance he should be ordered to return into banishment.
When he perceived the extreme danger into which the faith had been brought, inasmuch as the Westerns had been beguiled, and the Easterns were being overcome by means of wickedness, he, in three papers publicly presented, begged an audience of the king, in order that he might debate on points of faith in the presence of his adversaries. But the Arians opposed that to the utmost extent of their ability. Finally, Hilarius was ordered to return to Gaul, as being a sower of discord, and a troubler of the East, while the sentence of exile against him remained uncanceled.
But when he had wandered over almost the whole earth which was infected with the evil of unfaithfulness, his mind was full of doubt and deeply agitated with the mighty burden of cares which pressed upon it. Perceiving that it seemed good to many not to enter into communion with those who had acknowledged the Synod of Ariminum, he thought the best thing he could do was to bring back all to repentance and reformation. In frequent councils within Gaul, and while almost all the bishops publicly owned the error that had been committed, he condemns the proceedings at Ariminum, and frames anew the faith of the churches after its pristine form.
Saturninus, however, bishop of Arles, who was, in truth, a very bad man, of an evil and corrupt character, resisted these sound measures. He was, in fact, a man who, besides the infamy of being a heretic, was convicted of many unspeakable crimes, and cast out of the Church. Thus, having lost its leader, the strength of the party opposed to Hilarius was broken. Paternus also of Petrocorii, equally infatuated, and not shrinking from openly professing unfaithfulness, was expelled from the priesthood: pardon was extended to the others.
This fact is admitted by all, that our regions of Gaul were set free from the guilt of heresy through the kind efforts of Hilarius alone. But Lucifer, who was then at Antioch held a very different opinion. For he condemned those who assembled at Ariminum to such an extent, that he even separated himself from the communion of those who had received them as friends, after they had made satisfaction or exhibited penitence. Whether this resolution of his was right or wrong, I will not take upon me to say. Paulinus and Rhodanius died in Phrygia; Hilarius died in his native country in the sixth year after his return.
Source: Sacred History (New Advent)