Was the wife of Diocletian a secret Christian?

The only possible surviving portrait of the Empress Prisca from the Palace
of Diocletian at Split. Taken from Avrelia Prisca by Radonic.

Through the centuries, the name of Diocletian has become practically synonymous with the persecution of Christians. But is it possible that members of Diocletian’s own family, specifically his wife and daughter, were Christians themselves? The answer to this question is: “Yes.”

Whether they were good Christians or not—that is another question all together.

There are numerous legendary acts of the martyrs which identify the wife of Diocletian as a Christian. These tales, however, are unreliable at best. They identify the consort of Diocletian as "Serena" or "Eleuthera" or "Alexandra". As all of these stories were written long after the events, few scholars consider the details contained therein as facts. These tales do, however, seem to contain a kernel of truth.

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There is one contemporary ancient source that mentions the wife of Diocletian by name. This work was lost for most of antiquity, having been rediscovered again only in the 17th century. This singular source is entitled: On the Deaths of the Persecutors and it was written by the early 4th century Christian apologist, Lactantius. As primary sources go, On the Deaths of the Persecutors is outstanding, even though it was clearly not written by an objective observer. Lactantius was prominent in the court of Constantine the Great, to the extent that he was appointed tutor to Constantine’s eldest son, Crispus. But to be fair, Lactantius makes no pretenses to objectivity and presents his work not as a history but as a Christian polemic. On this blog, I have cited from this source at least half-a-dozen times in previous posts on topics such as the destruction of the church in Nicomedia, on the death of Constantius Chlorus, on the persecution of Decius, on Constantine’s vision of the cross, and on the Battle of the Milvian Bridge.

Following is the sad story of Prisca as related by Lactantius. In the first passage, Diocletian's junior emperor, Galerius, has fled the imperial palace in Nicomedia due to two fires which, he said, were set by Christians seeking vengeance for the persecutory edicts. As a response to these two fires, Diocletian sought to purge all secret Christians from his household, forcing everyone to sacrifice to the pagan gods:

And now Diocletian raged, not only against his own domestics, but indiscriminately against all; and he began by forcing his daughter Valeria and his wife Prisca to be polluted by sacrificing. Eunuchs, once the most powerful, and who had chief authority at court and with the emperor, were slain. [Lactantius, On the Deaths of the Persecutors, Chapter 15]

Strictly speaking, this passage does not prove that Prisca and Valeria were Christians, but if they weren’t it would be strange for Lactantius to mention them with such specificity. The obvious implication is that both Prisca and Valeria were secret Christians who lapsed into apostasy when forced by the emperor to sacrifice.

When Diocletian voluntarily retired from the imperial office in AD 305, it is unknown whether Prisca followed him to his fortress at Salona or remained at the imperial court at Nicomedia. Valeria, the daughter of Prisca and Diocletian, was the wife of Galerius, so it is possible that Prisca decided to remain with her at the court. In any event, when both Galerius and Diocletian died in AD 311, the two women were left at the mercy of Maximinus Daia, Galerius’s junior emperor. Scoundrel that he was, Daia sought to marry Valeria – who was technically his adopted mother – and when she rebuffed him, he seized her fortune, killed her attendants, and banished both Valeria and her mother Prisca from his dominions. [Lactantius, On the Deaths of the Persecutors, Chapter 39] This willingness to undergo such suffering rather than commit the equivalent of incest may indicate that Valeria, and Prisca by extension, had returned to their Christian beliefs.

About two years later, Daia was defeated by Licinius who then became sole Augustus of the East. Once he had achieved this position, Licinius ruthlessly sought out and killed any with even a tenuous claim to the imperial power in the East —including the wife and daughter of Diocletian. Lactantius describes the end of these unfortunate women as follows:

Valeria, too, who for fifteen months had wandered under a mean garb from province to province, was at length discovered in Thessalonica, was apprehended, together with her mother Prisca, and suffered capital punishment. Both the ladies were conducted to execution; a fall from grandeur which moved the pity of the multitude of beholders that the strange sight had gathered together. They were beheaded, and their bodies cast into the sea. Thus the chaste demeanor of Valeria, and the high rank of her and her mother, proved fatal to both of them. [Lactantius, On the Deaths of the Persecutors, Chapter 51]

As mentioned above, Prisca name is not found in any other ancient source aside from Lactantius. She does not even appear on any Roman coins of the age, though Valeria does appear. Scholars have speculated about this, and the two possibilities seem to be: 1.) that Prisca was merely a concubine and that Diocletian was not legally married to her, or 2.) that her memory was condemned (damnatio memoriae) by Licinius after her execution. The latter case seems more likely. If so, it is interesting to speculate about Lactantius's motive in mentioning Valeria and Prisca so specifically in a work written before Licinius's ultimate fall in AD 324, and even more interesting to consider why no subsequent writer, Christian or pagan, mentioned them at all.

Lactantius's treatment of these two women seems to demonstrate that he felt pity for their miserable fates. But given the overriding theme of his work — that those who persecute Christians, or side with persecutors, suffer horrible deaths — it's hard to make the case that either of them died as recognized Christians, let alone as martyrs for the Faith.