Synod of Milan
Athanasius of Alexandria, a staunch opponent of Arianism, was sentenced 353 at the Council of Arles. He refused, however, to recognize the judgment and requested together with Liberius, bishop of Rome, citing a canon of the Council of Serdica a new council. Liberius sent an embassy to Constantius, the Bishops of Calaris Lucifer and Eusebius of Vercelli belonged among others.
Constantius called 355 the Synod required to Milan, where he resided at the time. So it was possible that the Emperor was present at the council itself. At his instigation, the only item on the agenda was the case Athanasius. Eusebius of Vercelli, a supporter of Athanasius, suggested that the bishops should have an opportunity to sign the confession of Nicaea, and Bishop Dionysius of Milan already had had made copies of it for Bishops. This proposal led to clashes with the Arian bishops Valens of Mursa stolen Eusebius his copy of the confession and tore it up before his eyes. In response to the unrest moved Emperor Constantius, the Council of the Church, in which the bishops had gathered in his own palace, where he attended as an accuser of Athanasius the meetings.
As the followers of Athanasius himself still refused to sign the condemnation of Athanasius, Constantius responded with massive pressure: He threatened anyone who would not sign the judgment, draconian penalties. Then decided almost all of the 300 bishops present the condemnation of Athanasius as a traitor. Only Lucifer of Calaris, Dionysius of Milan, Eusebius of Vercelli, Paulinus of Trier and two legates of Liberius refused and were banished then.
Of the churches today, the Council of Milan is not recognized.