The heresiarch Arius was a Libyan by race and a protopresbyter of the Church of Alexandria. In 315, he began to blaspheme against the Son and Word of God, saying that He is not true God, consubstantial with the Father, but is rather a work and creation, alien to the essence and glory of the Father, and that there was a time when He was not. This frightful blasphemy shook the faithful of Alexandria. Alexander, his Archbishop, after trying in vain to correct him through admonitions, cut him off from communion and finally in a local council deposed him in the year 321. Yet neither did the blasphemer wish to be corrected, nor did he cease sowing the deadly tares of his heretical teachings; but writing to the bishops of other cities, Arius and his followers requested that his doctrine be examined, and if it were unsound, that the correct teaching be declared to him. By this means, his heresy became universally known and won many supporters, so that the whole Church was soon in an uproar.

Therefore, moved by divine zeal, the first Christian Sovereign, Saint Constantine the Great, the equal to the Apostles, summoned the renowned First Ecumenical Council in Nicaea, a city of Bithynia. It was there that the shepherds and teachers of the Church of Christ gathered from all regions in the year 325. All of them, with one mouth and one voice, declared that the Son and Word of God is one in essence with the Father, true God of true God, and they composed the holy Symbol of Faith up to the seventh article (since the remainder, beginning with "And in the Holy Spirit," was completed by the Second Ecumenical Council). Thus they anathematized the impious Arius of evil belief and those of like mind with him, and cut them off as rotten members from the whole body of the faithful.

Therefore, recognizing the divine Fathers as heralds of the Faith after the divine Apostles, the Church of Christ has appointed this present Sunday for their annual commemoration, in thanksgiving and unto the glory of God, unto their praise and honour, and unto the strengthening of the true Faith.

This great and renowned sovereign of the Christians was the son of Constantius Chlorus (the ruler of the westernmost parts of the Roman empire), and of the blessed Helen. He was born in 272, in (according to some authorities) Naissus of Dardania, a city on the Hellespont. In 306, when his father died, he was proclaimed successor to his throne. In 312, on learning that Maxentius and Maximinus had joined forces against him, he marched into Italy, where, while at the head of his troops, he saw in the sky after midday, beneath the sun, a radiant pillar in the form of a cross with the words: "By this shalt thou conquer." The following night, our Lord Jesus Christ appeared to him in a dream and declared to him the power of the Cross and its significance. When he arose in the morning, he immediately ordered that a labarum be made (which is a banner or standard of victory over the enemy) in the form of a cross, and he inscribed on it the Name of Jesus Christ. On the 28th Of October, he attacked and mightily conquered Maxentius, who drowned in the Tiber River while fleeing. The following day, Constantine entered Rome in triumph and was proclaimed Emperor of the West by the Senate, while Licinius, his brother-in-law, ruled in the East. But out of malice, Licinius later persecuted the Christians. Constantine fought him once and again, and utterly destroyed him in 324, and in this manner he became monarch over the West and the East. Under him and because of him all the persecutions against the Church ceased. Christianity triumphed and idolatry was overthrown. In 325 he gathered the First Ecumenical Council in Nicaea, which he himself personally addressed. In 324, in the ancient city of Byzantium, he laid the foundations of the new capital of his realm, and solemnly inaugurated it on May 11, 330, naming it after himself, Constantinople. Since the throne of the imperial rule was transferred thither from Rome, it was named New Rome, the inhabitants of its domain were called Romans, and it was considered the continuation of the Roman Empire. Falling ill near Nicomedia, he requested to receive divine Baptism, according to Eusebius (The Life of Constantine. Book IV, 61-62), and also according to Socrates and Sozomen; and when he had been deemed worthy of the Holy Mysteries, he reposed in 337, on May 21 or 22, the day of Pentecost, having lived sixty-five years, of which he ruled for thirty-one years. His remains were transferred to Constantinople and were deposed in the Church of the Holy Apostles, which had been built by him (see Homily XXVI on Second Corinthians by Saint John Chrysostom).

As for his holy mother Helen, after her son had made the Faith of Christ triumphant throughout the Roman Empire, she undertook a journey to Jerusalem and found the Holy Cross on which our Lord was crucified (see Sept. 13 and 14). After this, Saint Helen, in her zeal to glorify Christ, erected churches in Jerusalem at the sites of the Crucifixion and Resurrection, in Bethlehem at the cave where our Saviour was born, another on the Mount of Olives whence He ascended into Heaven, and many others throughout the Holy Land, Cyprus, and elsewhere. She was proclaimed Augusta, her image was stamped upon golden coins, and two cities were named Helenopolis after her in Bithynia and in Palestine. Having been thus glorified for her piety, she departed to the Lord being about eighty years of age, according to some in the year 330, according to others, in 336.

Saint Vincent was born in Toul in Gaul; he was the brother of Saint Lupus, Bishop of Troyes, who was a companion of Saint Germanus of Auxerre. Saint Vincent was first a soldier, then left the world to become a monk of the renowned monastery of Lerins, where he was also ordained priest. He is known for his Commonitorium, which he wrote as an aid to distinguish the true teachings of the Church from the confusions of heretics; his most memorable saying is that Christians must follow that Faith which has been believed "everywhere, always, and by all." He wrote the Commonitorium about the year 434, three years after the Third Ecumenical Council in Ephesus, which he mentions in the Commonitorium, and defends calling the holy Virgin Theotokos, "She who gave birth to God," in opposition to the teachings of Nestorius which were condemned at the Third Council.

Without identifying by name Augustine, Bishop of Hippo, Saint Vincent condemns his doctrine of Grace and predestination, calling it heresy to teach of "a certain great and special and altogether personal grace of God [which is given to the predestined elect] without any labour, without any effort, without any industry, even though they neither ask, nor seek, nor knock" (Commonitorium, ch. XXVI). See also Saint John Cassian, February 29; Saint John Cassian wrote his refutations before, and Saint Vincent after, the condemnation of Nestorius at the Third Council in 431, and the death of Augustine in 430. Saint Vincent reposed in peace about the year 445.