and extravagant disposition, nevertheless these vices were insignificant compared to other things. For he was the first of all the emperors since Caligula and Domitian to allow people to openly call him Dominus (Lord) and to worship him, and address him as a god.” (Aurelius Victor, De Caesaribus, 39.)
This is a gross exaggeration of Diocletian’s responsibility for initiating these ceremonial features, most of which can be traced back to earlier emperors. Even the designation of the emperor as dominus noster (our lord), which is what made modern historians dub the period the Dominate, in fact first appeared in the reign of Septimius Severus (193–211) and became quite general during the third century, well before Diocletian’s accession in 284.
Purple gradually became the imperial color. At the same time, the sceptre, long associated with Jupiter as chief god, became an adjunct to imperial costume from the time of the Severan emperors (combined reigns 193–235). The globe, symbol of rulership of the world, was to be seen on coins of Caracalla (r. 198–217) and Philip the Arab (r. 244–249.) To go with his elevated image, the emperor was even sometimes portrayed with a halo, or nimbus, a sign of divinity, as can be seen in representations of gods in wall-paintings from Pompeii (destroyed in the year 79) but only applied to living emperors from Constantine onward, notably on the Missorium (large ceremonial silver dish) of Theodosius I (r. 379–395.)
One innovation attributed to Diocletian by Ammianus Marcellinus, a much more reliable source than Aurelius Victor, is adoratio (doing obeisance) or supplicatio, before the emperor and kissing the hem of his purple robe. (Ammianus 15.5.18.) Some scholars have even found precedents for this among earlier emperors, notably Probus (r. 276–282), but the evidence for a Diocletianic origin is fairly strong. (See H. Stern 1954, pages 184–99.)
An oath by the emperor’s genius (attendant spirit) was now considered more binding even than one by the gods. (Dig. XII.2.13.6; ILS 618.) And coin legends of Aurelian boldly describe the living emperor as a god: IMPERATORI DEO ET DOMINO AVRELIANO. (Mattingly-Sydenham V.1.264, 299, nos. 305 ff.) Descriptions of Diocletian’s tetrarchy gave this formula a new twist. A marble milestone on the Via Egnatia on the way to Dyrrachium (later Durazzo, now Durres in Albania) in Illyricum is dedicated to: DIIS GENITIS ET/ DEORVM CREATORIBUS DD(OMINIS) NN(OSTRIS) DIOCLETIANO ET/ [MAXIMIANO INVIC]TIS AVGG(VSTIS) (To our Lords the invincible Diocletian and Maximian, offspring of gods and creator of gods) (CIL III.710 = ILS 629). The imperial pair are here described both as of divine descent and as the progenitors of gods, presumably the two Caesars who joined the tetrarchy in 293. From the early third century, everything connected with the emperor was described as sacrum or in Greek as hieron (sacred or holy).
However, certain other features associated with imperial claims to divinity are missing from the reign of Diocletian. One example is the radiate crown of the sun-god Apollo, first seen on coins portraying the deified Augustus and first worn on coins minted in his own lifetime by Nero (r. 54–68) (Mattingly-Sydenham, Vol. III, p. 178 f., and plate XI), followed, surprisingly enough, by coins minted in Antioch during the reign of Trajan (98–117). In the third century, this blatant symbol of the divinity of the living emperor was a regular feature on the imperial coinage, for example, under Aurelian (r. 270–275), but this fashion accessory was never adopted by Diocletian. (Rostovtzeff 1923, pp. 91–109.) A jewelled diadem, also associated with the sun-god, started appearing on coins of Gallienus (r. 253–268) but was also never affected by Diocletian though it became common later on.
The Imperial Cult
From the beginning of the Principate, there was always a tendency to revere the emperor in a religious sense. Though Augustus steadfastly refused divine honors for himself, he turned the deification of his adoptive father, Julius Caesar, to good account, styling himself divi filius (son of a god). Requests from the Greek-speaking provinces of Asia and Bithynia as early as 30 BCE to worship the future Augustus as sōter (savior) were deflected by combining this worship with that of Dea Roma (the personification of Rome as a goddess). (Cassius Dio, 51.20.6–7.) The loyalty of Roman citizens living in the provinces was to be demonstrated by worship not of the living ruler but of Dea Roma and Divus Julius. (Suetonius, Divus Augustus, 52; Tacitus, Annals, 4.37.)
The title Augustus, meaning “the sublime one,” initially used as a name, was redolent of divinity, associated as it was with Romulus, the eponymous mythical founder of Rome, who was worshiped as a god under the name of Quirinus. With a few exceptions, emperors were routinely deified upon death. Vespasian’s deathbed joke, cited in the previous chapter, “Dear me, I think I’m becoming a god,” represents a skeptical attitude towards imperial deification coupled with a recognition of it as a normal feature of Roman religion.
Sacrificial offerings were believed to propitiate the gods, and deified emperors were honored in the same way as the more established gods. The great majority of the population of the Roman Empire were not offended by the imperial cult. In the Eastern areas, particularly, there was a long tradition of worshiping even living rulers, going back well beyond their incorporation into the Roman Empire. So, the imperial cult formed a natural and integral part of the state religion.
In the West, and particularly in Italy, to avoid worshiping the living emperor, the emperor’s genius was worshiped instead. Every Roman paterfamilias (head of the family) was believed to have his own genius, which was not the same thing as his soul, but rather was his attendant spirit. As all genii were divine, they were a proper object of worship, sidestepping the worship of a living person.
But the worship even of dead emperors was anathema to both Jews and Christians, who abhorred it as the worship of a graven image or idolatry, categorically prohibited in the Ten Commandments. It is sometimes suggested that the Jews were given special exemption from participation in the imperial cult. This does not appear to be correct, but Jews were certainly dispensed from the sacrificial duties associated with the cult, being allowed to substitute for it prayers for the emperor’s well-being instead. (See Momigliano 1987.) The Jews could be recognized as a separate nation and so could normally enjoy the same toleration for their religion as was normally accorded by the Roman state religion to other communal religions. (See below.) But Christians did not form any distinct national, communal, or social element within the Empire. As far as the Roman authorities were concerned, Christians were simply members of Roman society, and their refusal to participate in the imperial cult, an integral part of the Roman state religion, could be regarded as seditious. So, the persecution of Christianity, a much rarer occurrence than is commonly believed (see below), was not motivated by any disagreement over doctrine, creed, or belief but was purely political.
The Great Persecution
Diocletian’s persecution of the Christians, formalized by an edict issued in 303, was no exception to this rule. Eusebius, the Church historian, admitted that there was no persecution of Christianity in the early part of the reign. (Eus. HE 8.1.1-6.) And Diocletian’s ire was first directed (in 302) only against the Manichees (Manicheans), a Christian sect with a good deal of support in the Eastern part of the Empire as well as in Egypt and North Africa. The Manichees were suspected of forming a pro-Persian fifth column, important at a time when a revived Persian Empire under the Sasanians posed a major threat to the Roman Empire.
But what was Diocletian’s motive for then turning on the mainstream Christians? It had nothing to do with religious dogma or belief but was a response to Christian refusal to serve in the army or, once enlisted, to participate in the sacrificial ceremonials of the imperial cult.
The thorough research of Professor Candida Moss has revealed the falsity of the age-old Christian tradition that Christians had been mercilessly and systematically hunted down, persecuted, and executed by the Romans for 300 years until this was halted by Constantine. Candida Moss puts the Great Pesecution in context in a passage quoted in Chapter 10. (Moss 2013, p. 129.)
Why does this matter? It is important in relation to Constantine’s later favoring of Christianity. (See Chapters