Arianism

Our first encounter with Arius is somewhere between 300-311 A.D., when he joined up with a group of heretics called Meletians. Evidently, he did not find what he was searching for; he left them.
He then managed to get himself ordained a deacon of the Catholic Church by Peter of Alexandria who was Bishop at the time. Evidently his loyalties were still with the Meletians, because when they were censured, he bitterly criticized the Church, and came out against her. He was excommunicated by the same Bishop who had ordained him deacon, Bishop Peter of Alexandria!