A “pirate king” who founded a breakaway state in Roman Britain inadvertently prolonged the Roman empire’s survival for centuries and secured the future of western civilisation as we know it.
That’s according to historian and archaeologist Simon Elliott, who argues in a forthcoming biography that the legacy of the former sailor Carausius has been neglected due to the smears of his rivals.
Carausius, a member of the Menapii tribe from modern-day Belgium, rose through the ranks of the Roman military and, under emperor Maximian, built and commanded a fleet that cleared the North Sea and English Channel of Saxon raiders targeting Britain.

Accused by Maximian of colluding with the Saxons and seizing their spoils for his own enrichment, he declared himself emperor in Britain and northern Gaul in 286AD rather than face execution. Carausius’s usurpation followed decades of civil wars with rival military strongmen vying for control until stability was restored by Diocletian, who had appointed Maximian co-emperor in the west.
For creating a state centred on Britain outside of imperial control, Carausius has sometimes been described as the first Brexiteer. However, Elliott said Carausius always emphasised his Romanitas or Roman-ness — even minting coins boasting of restoring lost Roman glory.
Elliott argues in Roman Britain’s Pirate King that Carausius’ success, and his clever public relations, were an embarrassment that forced Rome to retake Britain at a time when the remote and troublesome British provinces might otherwise have been cut loose. “Without Carausius’ usurpation, given the far wider internal and external troubles which beset the Roman world throughout the 4th century, Britain might soon have been forgotten and perhaps abandoned early.”
This obscure usurper from the remotest part of the Roman empire, the Wild West of the northwest corner, reinvigorates the imperial centre by challenging it
Simon Elliott
Maximian’s initial attempt to crush Carausius failed after an invasion fleet he had assembled was destroyed in circumstances that are now mysterious. The fleet may have been defeated by Carausius’ navy or destroyed by a storm. Elliott speculates that Carausius, a canny operator, may have paid marauding Franks to scuttle the fleet while it was still at anchor in the Rhine Delta.
The Menapian’s fate was sealed after his bridgehead at Boulogne was taken by the new caesar, or junior emperor, Constantius Chlorus, in 293. Discredited, he was murdered by one of his senior officials, the shadowy Allectus, whose subsequent rule of Britain ended after Constantius invaded and brought its provinces back into the fold three years later.
Elliott believes that Constantius’ victory in Britain, dividing his forces and utilising a clever feint, gave him prestige that contributed to troops proclaiming his son Constantine emperor at York in 306. Constantine’s administrative reforms and adoption of Christianity as the state religion in turn had momentous consequences that helped prolong the empire’s survival to 476 in the west and 1453 in the east, and the survival of aspects of Roman culture in post-Roman states.
He said the Carausian revolt didn’t only pave the way for Constantine, but, by ensuring that Britain was fully reintegrated into the empire, allowed the island to become a major supplier of grain to troops when continental supply chains were broken by barbarian incursions across the Rhine during the 350s. Without this lifeline he believes the western empire might have fallen much earlier than it did, before a strongly rooted church could survive to carry on Rome’s legacy.

He added: “The story of Carausius is one of the great untold stories of British history. This obscure usurper from the remotest part of the Roman empire, the Wild West of the northwest corner, reinvigorates the imperial centre by challenging it, and ends up helping to extend the whole thing for another 200 years in the west — crucial years for setting up the future of western civilisation — and over 1,000 years in the east.”
Carausius must have been popular, and considered effective before his defeat at Boulogne, he said, or he could not have survived for so long. Romano-Britons may have felt “unloved” by previous distant rulers, whereas Carausius addressed them directly with his promises.
The usurper made his mark with a massive building programme centred on the construction and strengthening of defences around London and the southeast coast, some of which survive as ruins. Elliott believes that Carausius’ work on coastal defences, including “Saxon Shore” forts at sites such as Richborough, was intended to stop an imperial invasion force rather than Saxon raiders.
“It’s the last major public building programme in the history or Roman Britain and it’s on a scale to match anything that’s gone previously,” he said. “It’s also very unusual because earlier programmes were before the Crisis of the Third Century and were largely funded by civic officials and local aristocrats who were encouraged, often forcefully, to spend their wedge celebrating Romanitas. This was a public building programme paid for by the state.”
Carausius also established Roman Britain’s first official mint, at London, producing coins of higher quality than those of the empire. Coin inscriptions appealed to both Roman and Romano-British identities and included references to quotes from Virgil, such as RSR (for Redeunt Saturnia Regna: ‘the kingdom of Saturn returns’) that could only have been appreciated by an educated elite.
If Carausius was a clever propagandist in his lifetime, it was his enemies who had the last word. Elliott said the depiction of Carausius as a venal “pirate on the run” in imperial speeches and histories, shaped the way he was remembered, although the allegations of corruption may have been trumped up.
He added that, following Carausius’ success against the Saxons, Maximian might simply have feared that the successful commander was too popular with troops and the British public. “We only see his personal details through contemporary writing, which is totally negative.”
He hopes that his reappraisal may make Carausius “the second most famous Belgian after Poirot”.