For a general introduction to Eusebius and the Ecclesiastical History, please see the commentary on I.6.6-11.

After describing the events preceding 260 CE, Eusebius turns in his eighth book of the Ecclesiastical History from writing about the events of the past to relating the events of his own lifetime. He therefore ceases to replicate the accounts of other written sources, which has been a major feature of the former section of his history, and relies more upon his own observations, knowledge, and conversations with contemporaries (although he does still use and quote Dionysius of Alexandria) (see Timothy Barnes, Constantine and Eusebius, p. 143).

This passage attempts to briefly overview a transitional period within the empire. Eusebius traces events from a time when there was relative peace for Christians and prosperity for Rome, to the so-called “Great Persecution” of Christians under Diocletian, and the unsettled period for the Roman government which proceeded Diocletian’s abdication in 303 CE. In the midst of the account, in Eusebius’s description of Constantius and his son Constantine, the great victory for Christianity that was to come—Constantine’s conversion and Christianisation of the empire—is introduced. This will eventually form the climax of Eusebius’s history. The events leading up to this begin at IX.9.1, with Constantine and Licinius’s civil war with Maxentius, and continue for the remainder of book IX. Book X then describes the peace that Christianity enjoyed in the empire once again, ultimately ending with Constantine’s victory over Licinius and the uniting of the empire under one emperor again; this time, one chosen by and receptive to the one true God.

Eusebius opens verse 9 by remarking that Christianity had recently enjoyed relative peace within the empire, and tolerance from Roman authorities, who were able to enjoy their time participating in festivals and public games. Eusebius has already described how Christianity was able to grow and exist alongside Roman religion in many places after Gallienus rescinded his father Valerian’s edict which had led to the persecution of Christians. For example, there were numerous Christians in the Roman army (VII.11.20), and Christian provincial governors who were discreetly relieved from having to sacrifice when conducting public business (VIII.1.2). Indeed, book VIII opens with the following proclamation: “It is beyond our ability to describe in a suitable manner the extent and nature of the glory and freedom with which the word of piety toward the God of the universe, proclaimed to the world through Christ, was honored among all men, both Greeks and barbarians, before the persecution in our day.” This said, Christianity remained technically a capital punishment, as exemplified by the story of a Christian Roman soldier from Caesarea, Marinus, denied a promotion to centurion when revealed as a believer, and subsequently executed shortly after 260 CE (VII.15). Verse 10 of the present passage states that while Christianity enjoyed a greater degree of freedom, the Roman government was at this time enjoying a time of prosperity itself, with its authority increasing on a daily basis. The message that Eusebius gives, therefore, is that Christianity and Rome are perfectly capable of co-existing successfully, as long as those in authority allow it. It would be stretching things to suggest that Eusebius argues here for a direct correlation between Christianity’s flourishing and that of the empire (as other Christian authors had done), but he certainly does not see the two as fundamentally incompatible, something which should always be remembered in relation to the fact that Eusebius would witness the Christianisation of the empire during his own lifetime.

Unfortunately, however, this time of relative harmony between Rome and Christianity was not to last, broken by the persecution under Diocletian which began in 303 CE (some scholars have suggested that Christian authors have greatly exaggerated the scale of Diocletian’s persecution; for instance, see the influential article of Geoffrey de Ste. Croix, “Why Were the Early Christians Persecuted?” For some Christian sources related to the so-called “Great Persecution,” see Inscriptiones Christianae Graecae 3621; Peter of Alexandria, Canonical Epistle V-VII). Eusebius’s own (highly polemical) account of the martyrdoms occurring in Caesarea during this persecution are found in his famous Martyrs of Palestine, the shorter recension of which appears as an appendix to chapter VIII of the Ecclesiastical History (for a recent discussion of Eusebius’s rhetorical aims in the Martyrs of Palestine, see James Corke-Webster, “A Literary Historian”). The Diocletianic persecution is not elaborated upon here, however. Rather, Eusebius’s focus for the remainder of the passage will be various emperors and their relative characters, introduced by the statement that in the second year of the persecution (304 CE), unrest broke out within the Roman government after Diocletian fell ill. He abdicated this same year, and his colleague Maximian retired with him. A brief overview of some historical points will aid the contextualisation of the remainder of this passage.

Diocletian’s reign had seen the creation of the tetrarchy (a system whereby two Augusti and two Caesars under them shared rule of the empire, which was divided into West and East; recognised by Eusebius in verse 11 above). Shortly after his accession, Diocletian had already made his junior colleague, Aurelius Maximianus (Maximian), Caesar, and the two had effectively shared the responsibility of rulership (see Alan Bowman, “Diocletian and the First Tetrarchy,” p. 69-70). Whether or not this was a first step in a grander plan to later form the tetrarchy, or simply a response by Diocletian to excessive responsibility, is debated. The evidence for the first argument depends largely on the claim of the Christian author Lactantius (On the Deaths of the Persecutors XVIII.5), and for many scholars, the second option makes more sense, especially since Maximian was soon deployed to Gaul and Britain to deal with troubles probably caused by the pressure of taxation (the Bagaudae) revolting under the pressure of taxation (e.g. Bowman, “Diocletian and the First Tetrarchy,” p. 69-70). In 293 CE, two Caesars were appointed as members of the imperial college: Flavius Constantius, who had been Maximian’s praetorian prefect in the West, and Galerius Maximianus, who was placed in charge of defending the eastern territories of Syria, Palestine, and Egypt (there is not space to discuss the specifics of the tetrarchy and the events leading up to it here, but for an overview, see Barnes, Constantine and Eusebius, p. 4-8; for more detail, see, for example, Roger Rees, Diocletian and the Tetrarchy, which examines Diocletian’s reorganisation of the empire thematically in terms of the military, economy, administration, and religion; the collection of essays in Demandt, Goltz, and Schlange-Schöningen’s, Diokletian und die Tetrarchie are also useful in this regard). Galerius and Constantius were to become Augusti following the retirement of Diocletian and Maximian. Maximian’s son Maxentius and Constantius’s eldest son Constantine then became Caesars (technically, the Caesar Severus should have succeeded Constantius, but Constantine was immediately named as his successor, and hailed as Augustus by the army). Licinius (promoted to Augustus by Galerius in 308 CE), mentioned in verse 14 of the present passage, became a bitter rival of Constantine’s, and was eventually executed after a civil war which began in 314 CE.

Verses 12 and 13 heap praises upon Constantius and his son Constantine for their piety. The former is celebrated by Eusebius for his favourable disposition towards the Christians. Eusebius is of course incorrect in his statement that Constantius was the first emperor to being given divine honours after his death, but rather Constantius was the first of the four ruling figures at that time. Because Constantius was the father of Christianity’s first true imperial champion, it is therefore perhaps not surprising that he is remembered in Christian literature as a Christian himself. In addition to the laudatory picture which Eusebius paints of him in the present extract from the Ecclesiastical History, his Life of Constantine I.13-18 claims that Constantius only pretended to be a pagan, and would have no part himself in the persecutions under Diocletian. As Averil Cameron explains, however, Eusebius greatly exaggerates matters here. While Constantius may have been less enthusiastic about the persecution of Christians, we cannot follow Eusebius in naming him as one himself (“The Reign of Constantine,” p. 91). While Eusebius’s great panegyric on the emperor Constantine was to come later, here we see an early hint of this, which establishes a heritage of piety and good relations with Christianity stemming from Constantine’s own father. Vitally significant is that Eusebius emphasises that while the Roman soldiers were responsible for proclaiming Constantine the sole, supreme emperor of Rome, the one true Augustus, this was something which God had already done. The notion of a divine plan for the Christianisation of the Roman empire is therefore alluded to, a notion which has been built up from the very beginning of the Ecclesiastical History (see, for instance, the commentary on I.6.6-11).