King Arthur was Roman? Extraordinary Theory

For centuries, King Arthur has stood somewhere between history and legend. The stories describe a great warrior who defended Britain, defeated enemies, and became one of the most famous figures of the medieval imagination. But behind the legend, historians have searched for a real person who might have inspired the story. One candidate has a particularly intriguing name.

Lucius Artorius Castus was a real Roman military commander. His career is recorded on a damaged inscription discovered at Podstrana, on the Adriatic coast of modern Croatia. It tells us that he served in several legions, commanded a Roman fleet, led forces associated with Britain, and eventually governed the province of Liburnia. And his name “Artorius” sounds remarkably close to Arthur. Could this Roman officer have been the man behind the legend?

The Man in the Inscription

Almost everything we know about Castus comes from inscriptions. The larger of them was found at Podstrana, near the ancient settlement of Epetium in Roman Dalmatia. Today, two surviving fragments are associated with the Church of St Martin. The inscription was part of Castus’s funerary monument and records an unusually detailed military career. The surviving text dates the monument broadly to the Antonine–Severan period, roughly AD 180–230, although that does not necessarily give us the exact dates of Castus’s life or individual commands.

The career it records is impressive. Castus had served as a centurion in four legions:

• Legio III Gallica
• Legio VI Ferrata
• Legio II Adiutrix
• Legio V Macedonica

He then became primus pilus, the senior centurion of a legion. After that, he held increasingly important commands, including the Misenum fleet based in Italy and, later, Legio VI Victrix, stationed in Britain. Finally, he became a procurator of Liburnia with the authority associated with a senior provincial administrator. No, this was not the career of an ordinary soldier. By the end of it, Lucius Artorius Castus had risen into the upper ranks of the Roman military and administrative establishment.

Castus and Britain

The inscription describes Castus as dux of forces connected with Britain. The exact wording is damaged, but it clearly associates him with a military command involving troops from Britain. That gives us two important pieces of evidence. Artorius was a real Roman commander, and he had a military connection with Britain. Those two facts are not disputed, but almost everything besides them is.

One damaged section of the inscription contains the words adversus Arm…s — “against the …” followed by a name beginning with Arm-. For more than a century, scholars generally reconstructed this as a reference to the Armoricans, peoples of northwestern Gaul. But French epigraphist Xavier Loriot argued that the inscription should instead be read as referring to the Armenians. The surviving stone is too damaged for the question to be treated as completely settled.

That matters because the two interpretations place Castus’s military expedition in very different parts of the Roman world. So we should not confidently tell readers that Castus definitely conquered Brittany or Armorica. The inscription does not allow that certainty.

Then Came King Arthur

The connection between Castus and King Arthur was proposed in the early twentieth century.

In 1925, American scholar Kemp Malone examined the Roman name Artorius and its possible relationship to the name of King Arthur. He noted that Lucius Artorius Castus was a Roman officer with a documented connection to Britain and argued that he was the most plausible historical figure behind certain elements of the Arthurian tradition. The theory is attractive for obvious reasons.

And there is a genuine linguistic argument behind the connection. Artorius is a Roman family name, and scholars have examined whether its transformation into Arthur is linguistically possible in the Brittonic languages. Malone argued that it was. But a possible linguistic connection is not proof of historical identity. And this is where the theory begins to encounter serious problems.

The Problem With Making Castus King Arthur

The biggest problem is chronology. Castus belongs to the Roman world of the second or early third century AD. The historical setting usually proposed for an Arthurian war leader is several centuries later, during the turbulent period following the collapse of Roman authority in Britain. That gap is enormous. There is also no ancient source saying that Lucius Artorius Castus was King Arthur.

No Roman historian identifies him with the legendary king. No surviving British source makes the connection. And no inscription links Castus to the Arthurian tradition. Arthur himself is a difficult historical figure. Even the origins of the Arthur tradition remain disputed, and historians have proposed several different explanations for how the legendary character developed. Some scholars have entertained Castus as a possible source, while others have regarded the identification as highly speculative.

So, what do we know?

Lucius Artorius Castus was real. King Arthur became a legendary figure. The claim that one inspired the other remains unproven and, to be honest, highly unlikely.

A Roman Career Worth Remembering

Ironically, Castus does not need King Arthur to make his story remarkable. His own career was extraordinary. He served in four different legions, rose through the centurionate, became primus pilus, commanded the Misenum fleet, and eventually commanded Legio VI Victrix in Britain. He later held high administrative office in Liburnia. The inscription even records that he possessed ius gladii, the authority to impose capital punishment.

This was a man who had climbed almost as high as a Roman provincial military career could take him. And then, centuries after his death, another name began to dominate the history and mythology of Britain. King Arthur. And he is the main reason many decided to check this article. I think we should hold these two figures separate. One as historically certain, and the other legendary. Lucius Artorius Castus was not a fictional hero invented by medieval storytellers. He was a real Roman commander, whose career is carved into stone in Dalmatia. And King Arthur… Well, he is one of the greatest myths of that period.

Perhaps the name Artorius survived and was transformed through British tradition. Perhaps Castus’s career contributed something to stories that were later reshaped into Arthurian legend. Or perhaps the resemblance is simply one of history’s great coincidences.