Dom Prosper Guéranger:
Peter, successor of Saint Theonas in the See of Alexandria, was by his learning and holiness the glory of Egypt and the light of the whole Church of God. Such was his courage under the terrible persecution raised by Maximian Galerius that the example of his admirable patience strengthened a great many in Christian virtue. He was the first to cut off from the communion of the faithful, Arius, deacon of Alexandria, for favouring the schism of the Meletians. When Peter had been condemned to death by Maximian, the priests Achillas and Alexander came to him in prison to intercede for Arius, but the bishop answered that during the night Jesus had appeared to him with His garment torn, and on his asking the cause, had replied: “Arius has rent my garment, which is the Church.” He then foretold that they two would succeed him in turn in the episcopate, and forbade them ever to receive Arius to communion, for he knew that he was dead to God. The truth of this prophecy was soon proved by the event. Peter was beheaded, and thus went to receive the crown of martyrdom on the sixth of the Calends of December, in the twelfth year of his episcopate. Let us offer our homage and prayers to the great bishop whom the Church thus commemorates today. For a long time he went by the name of Peter the Martyr, until in the thirteenth century another Peter martyr, himself illustrious among all, came to claim the title, leaving his glorious brother to be known as Saint Peter of Alexandria.Also on this day according to the ROMAN MARTYROLOGY:
At Alexandria, in the same persecution, the holy martyrs Faustus, priest, Didius and Ammonius. Likewise, Phileas, Hesychius, Pachomius and Theodore, Egyptian bishops, with six hundred and sixty others, who the sword of persecution sent to heaven.
At Nicomedia, in the time of Constantius, St. Marcellus, a priest, who died a martyr by being hurled down from a rock.
At Padua, St. Bellinus, bishop and martyr.
At Rome, St. Siricius, pope and confessor, celebrated for his learning, piety and zeal for religion, who condemned various heretics, and published salutary laws concerning ecclesiastical discipline.
At Autun, St. Amator, bishop.
At Constance, St. Conrad, bishop.
In the diocese of Rheims, the birthday of St. Basolus, confessor.
At Adrianople in Paphlagonia, St. Stylian, anchoret, renowned for miracles.
In Armenia, St. Nicon, monk.
At Rome, St. Leonard of Port Maurice, confessor, of the Friars Minor of St. Francis, of the Strict Observance. He was remarkable for zeal, for he spent several years with extraordinary success in conducting his holy expeditions through Italy for the conquest of souls. He was ranked among the blessed by Pope Pius VI, and among the saints by Blessed Pius IX during the solemnities connected with the eighteenth centenary of the princes of the Apostles, Saints Peter and Paul.
And in other places, many other holy martyrs, confessors and virgins.
Thanks be to God.