An alt-right commentator who complained about the BBC portraying Roman Britain as ethnically diverse has sparked a row with a historian on Twitter.

Paul Joseph Watson (PJW), editor of alt-right website InfoWars, shared a screengrab of a BBC educational video on life in Britain, suggesting it was inaccurate.

“Thank God the BBC is portraying Roman Britain as ethnically diverse,” he tweeted. “I mean, who cares about historical accuracy, right?”

Step forward writer and historian Mike Stuchbery, who gave PJW a quick history lesson on ethnic diversity in Roman Britain.

“Roman Britain was ethnically diverse, almost by design. To begin, occupying legions were drawn from other parts of the Empire,” Stuchbery responded.

“Every year we dig up new remains that suggest that Roman Britain, anywhere larger than a military outpost, was an ethnically diverse place.”