Philip, who is accused by the historians of being the author of Gordian’s death, succeeded him on the throne in 244; but he is only known in the history of Egypt by his Alexandrian coins, which we find with the dates of each of the seven years of his reign, and these seem to prove that for one year he had been associated with Gordian in the purple. In the reign of Decius, which began in 249, the Christians of Egypt were again harassed by the zeal with which the laws against their religion were put in force. The persecution began by their fellow-citizens informing against them; but in the next year it was followed up by the prefect Æmilianus; and several Christians were summoned before the magistrate and put to death. Many fled for safety to the desert and to Mount Sinai, where they fell into a danger of a different kind; they were taken prisoners by the Saracens and carried away as slaves. Dionysius, the Bishop of Alexandria, himself fled from the storm, and was then banished to the village of Cephro in the desert. But his flight was not without some scandal to the Church, as there were not a few who thought that he was called upon by his rank at least to await, if not to court, the pains of martyrdom. Indeed, the persecution was less remarkable for the sufferings of the Christians than for the numbers who failed in their courage, and renounced Christianity under the threats of the magistrate. Dionysius, the bishop, who had shown no courage himself, was willing to pardon their weakness, and after fit proof of sorrow again to receive them as brethren. But his humanity offended the zeal of many whose distance from the danger had saved them from temptation; and it was found necessary to summon a council at Rome to settle the dispute. In this assembly the moderate party prevailed; and some who refused to receive back those who had once fallen away from the faith were themselves turned out of the Church.
Dionysius had succeeded Heraclas in the bishopric, having before succeeded him as head of the catechetical school. He was the author of several works, written in defence of the trinitarian opinions, on the one hand against the Egyptian Gnostics, who said that there were eight, and even thirty, persons in the Godhead, and, on the other hand, against the Syrian bishop, Paul of Samosata, on the Euphrates, who said that Jesus was a man, and that the Word and Holy Spirit were not persons, but attributes, of God.
But while Dionysius was thus engaged in a controversy with such opposite opinions, Egypt and Libya were giving birth to a new view of the trinity. Sabellius, Bishop of Ptolemais, near Cyrene, was putting forth the opinion that the Father, Son, and Holy Spirit were only three names for the one God, and that the creator of the world had himself appeared upon earth in the form of Jesus. Against this opinion Dionysius again engaged in controversy, arguing against Sabellius that Jesus was not the creator, but the first of created beings.
The Christians were thus each generation changing more and more, sometimes leaning towards Greek polytheism and sometimes towards Egyptian mysticism. As in each quarrel the most mysterious opinions were thought the most sacred, each generation added new mysteries to its religion; and the progress was rapid, from a practical piety, to a profession of opinions which they did not pretend to understand.
During the reigns of Gallus, of Æmilius Æmilianus, and of Valerian (A.D. 251-260), the Alexandrians coined money in the name of each emperor as soon as the news reached Egypt that he had made Italy acknowledge his title. Gallus and his son reigned two years and four months; Æmilianus, who rebelled in Pannonia, reigned three months; and Valerian reigned about six years.
Egypt, as a trading country, now suffered severely from the want of order and quiet government; and in particular since the reign of Alexander Severus it had been kept in a fever by rebellions, persecutions, and this unceasing change of rulers. Change brings the fear of change; and this fear checks trade, throws the labourer out of employment, and leaves the poor of the cities without wages and without food. Famine is followed by disease; and Egypt and Alexandria were visited in the reign of Gallus by a dreadful plague, one of those scourges that force themselves on the notice of the historian. It was probably the same disease that in a less frightful form had been not uncommon in that country and in the lower parts of Syria. The physician Aretæus describes it under the name of ulcers on the tonsils. It seems by the letters of Bishop Dionysius that in Alexandria the population had so much fallen off that the inhabitants between the ages of fourteen and eighty were not more than those between forty and seventy had been formerly, as appeared by old records then existing. The misery that the city had suffered may be measured by its lessened numbers.
During these latter years the eastern half of the empire was chiefly guarded by Odenathus of Palmyra, the brave and faithful ally of Rome, under whose wise rule his country for a short time held a rank among the empires of the world, which it never could have gained but for an union of many favourable circumstances. The city and little state of Palmyra is situated about midway between the cities of Damascus and Babylon. Separated from the rest of the world, between the Roman and the Parthian empires, Palmyra had long kept its freedom, while each of those great rival powers rather courted its friendship than aimed at conquering it. But, as the cause of Rome grew weaker, Odenathus wisely threw his weight into the lighter scale; and latterly, without aiming at conquest, he found himself almost the sovereign of those provinces of the Roman empire which were in danger of being overrun by the Persians. Valerian himself was conquered, taken prisoner, and put to death by Sapor, King of Persia; and Gallienus, his son, who was idling away his life in disgraceful pleasures in the West, wisely gave the title of emperor to Odenathus, and declared him his colleague on the throne.
No sooner was Valerian taken prisoner than every province of the Roman empire, feeling the sword powerless in the weak hands of Gallienus, declared its own general emperor; and when Macrianus, who had been left in command in Syria, gathered together the scattered forces of the Eastern army, and made himself emperor of the East, the Egyptians owned him as their sovereign. As Macrianus found his age too great for the activity required of a rebel emperor, he made his two sons, Macrianus, junior, and Quietus, his colleagues; and we find their names on the coins of Alexandria, dated the first and second years of their reign. But Macrianus was defeated by Dominitianus at the head of a part of the army of Aureolus, who had made himself emperor in Illyricum, and he lost his life, together with one of his sons, while the other soon afterwards met with the same fate from Odenathus.