"An ancestral relationship links you with the deified Claudius" ~ Was Constantine the Great a relative of Claudius II Gothicus?

Gloria Romanorum ^ | November 6, 2026 | Florentius

[Antoninus]

Many years ago, I wrote a brief post on the birthday of the brief-reigning Roman Emperor Claudius II Gothicus. This post was little more than a summary of his reign (from AD 268-270) based on the scanty sources we have for that period during the so-called Crisis of the Third Century. At the end, however, I included a notice about the supposed familial link between Claudius and Constantine. Claudius has been on my mind a bit lately, and so I decided to ask my preferred AI bot what it thought of this thesis. The initial result didn't surprise me:

Constantine the Great claimed to be the grand-nephew of Emperor Claudius II Gothicus (reigned 268–270 AD), but modern historians view this genealogical link as an invented political fiction.

The AI bots always default to the "modern historians" because that's what they're fed with. Of course, most modern historians (Charles Odahl excepted) have a barely concealed animus toward Constantine that rivals only Zosimus in its zeal. As a result, they often default to explanations of historical events that throw the darkest possible shade on that particular emperor.

In the case of Constantine's disputed familial relationship to Claudius II, I feel like the verdict of "invented political fiction" is perhaps a hasty one.

Why would Constantine need to invent this relationship? The argument has been to this point that Constantine needed some sort of grand dynastic heritage to bolster his own claim to the imperial throne against his rivals like Maxentius and Licinius. But he already had such a claim. His own father, Constantius I Chlorus, was one of the Tetrarchs created by Diocletian. Constantius was appointed Caesar by Diocletian in AD 293, and would rule as Augustus in his own right from AD 305 until his death in Britain a year later. Constantine was elevated to the imperial dignity by his father's army in Britain, an accession that was later ratified by the senior emperor, Galerius, in Nicomedia.

The idea that Constantine needed to create a fictional propaganda alliance between himself and an emperor who reigned for two years, and who, according to the Saint Valentine legend, was a persecutor of Christians besides, seems strange, particularly given that folks who remembered the reign of Claudius II were still alive at the time.

Let's review the sources of this putative tie which are pretty extensive. First, there are numerous mentions of the connections in the panegyrical literature, written in the 310s AD during the early years of Constantine's reign in the West, some 40 years after the death of Claudius. I quoted one of these excerpts in the original post here. Below is another one, dated from the year AD 312, which is noteworthy in that it is so pedestrian:

[R]ecently, to pass over intervening events, they [the Aedui] alone called upon the deified Claudius, your ancestor, to recover the Gauls, and, what must be mentioned especially, a very few years ago they received the most numerous benefactions from your father, some realized by deeds; some they rejoiced in as signifed intentions....Consider, I beseech you, O Emperor, how serious a thing it was for the Aedui to be the first to urge the deified Claudius, your forefather, to recover the Gauls. Awaiting his help, besieged for seven months, and suffering piteously all the miseries of famine, they finally abandoned their gates to be broken down by the rebel Gauls, only when, exhausted, they could no longer mount guard over them. [Taken from: Panegyrici Latini by Nixon and Rogers]

The family tie is also mentioned in the notoriously unreliable Historia Augusta, written about 100 years after the death of Claudius:

Since we have now described his [Claudius's] achievements in war, we must tell a few things, at least, concerning the kindred and the family of Claudius, lest we seem to omit what all should know: Now Claudius, Quintillus, and Crispus were brothers, and Crispus had a daughter Claudia; of her and Eutropius, the noblest man of the Dardanian folk, was born Constantius. [Magie (transl.): Historia Augusta]

This would make Constantius the grandnephew of Claudius II, the child of his niece. Given how freely the Historia Augusta mixes fact with outright fiction, however, this passage, along with the numerous mentions of Constantius within the rest of the HA's biography of Claudius II, can not be considered anything but the flimsiest and most dubious of evidence.

Perhaps the most convincing piece of evidence comes from the pen of Eutropius who was not specifically a partisan of Constantine or his sons, and also not a Christian. Writing about 100 years after the death of Claudius II, Eutropius claims:

Diocletian promoted Maximian Herculius from the dignity of Caesar to that of emperor, and created Constantius and Maximian Galerius Caesars, of whom Constantius is said to have been the grand-nephew of Claudius by a daughter, and Maximian Galerius to have been born in Dacia not far from Sardica. [Breviarium of Eutropius, Book IX, Chapter 22]

Considering Eutropius had little interest in proclaiming Constantine's bona fides, a full thirty plus years after his death, and ten years after the unlamented death of Constantius II, the last of Constantine's sons, he could easily have omitted this statement if he felt it was in any way false or even suspect.

The numismatic evidence is also fascinating. In AD 317 or 318, a series of coins were stamped in the mints of the West celebrating the deceased imperial ancestors of Constantine, specifically: his father, Constantius I Chlorus; his father-in-law, the previously condemned Maximianus Herculius; and Claudius II Gothicus.

For a really nice run-down of the surviving epigraphic and numismatic evidence of the familial cult of Constantine, visit Constantine's Imperial Cult at the Key to Umbria site.

So in case it's not crystal clear by this point, I'm not buying the "political fabrication" argument put forth by a consensus of modern scholars. I understand the rationale behind the thesis, but I think it is too clever by half. It attempts to jam Constantine the Christian Roman into the mold of a very 20th century pragmatic generalissimo/politician, and that doesn't seem to fit in with the tough but often ethereal character of Constantine as I have come to understand it. While Constantine was not a perfect human being, pretending to a lineage that everyone around him knew was phony seems like the kind of petty stolen valor silliness that would have been below him.

If I have to break with the much-respected Prof. Odahl in this opinion, then so be it.

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TOPICS: History
KEYWORDS: christianrome; claudiusii; constantine; lateromanempire

[Antoninus]

Here's some historical arcana for your morning reading.

[Antoninus]

GGG ping.

[lee martell]

Oh, you’re talking about ROMAN-Romans, not people like
Marcellus, Antoine and Titus from the south side of Chicago.
That’s different!

[sauropod]

read

[Vaquero]

Incontinentia Buttocks…wife of Biggus Dickus

[Cronos]

maybe it was because of his successes against the Alemanni and the Goths?

[Opinionated Blowhard]

The idea that Constantine needed to create a fictional propaganda alliance between himself and an emperor who reigned for two years, and who, according to the Saint Valentine legend, was a persecutor of Christians besides, seems strange,

In concept, Constantine trying to create a connection to a prominent historic emperor is not surprising no matter what he did to Christians. Constantine was a practical politician and power player above all, not a true believing Christian. If a lineage to Claudius Gothicus created some credibility, he would grab for it.

As an aside, my favorite story about creating a prominent lineage for an emperor was the one created for Vespasian. His courtiers presented him with a family tree that traced his lineage back to Hercules. It was reported that Vespasian burst out laughing when he heard this. A very down to earth emperor who could smell BS when he saw it.